Here, at long last, is the article I promised you in The Forgotten Jews almost 3 months ago.
The Ashkenazis, otherwise known as the Ashkenazim, make up the vast majority of world Jewry. They come from Eastern Europe, particularly (but not exclusively) Germany. The second-largest group is the Sephardim, who come from Spain, followed by the Mizrahim, who stayed in the Middle East.
However, there is a theory – founded in the 1800s, and holding some small degree of popularity today – that the Ashkenazim are not Jews; but rather, Gentile descendants of the Khazars. The Khazars were a Turkish people whose empire, known as Khazaria, lasted from about 650 AD to 969 AD.
Is this claim true, or false?
This argument is used fairly frequently for arguing a Khazarian (or at least Gentile) origin for the Ashkenazim. It derives from the following passage:
The sons of Japheth were Gomer, Magog, Madai, Javan, Tubal, Meshech, and Tiras. The sons of Gomer were Ashkenaz, Riphath, and Togarmah. (Genesis 10:2-3, NKJV)
Therefore, so it is argued, because they called themselves Ashkenazim, they must be Ashkenaz’s descendants. This argument immediately loses all credibility when one examines the indisputable, recorded history of how the different Jewish groups got their names:
In the Yoma tractate of the Babylonian Talmud the name Gomer is rendered as Germania, which elsewhere in rabbinical literature was identified with Germanikia in northwestern Syria, but later became associated with Germania. Ashkenaz is linked to Scandza/Scanzia, viewed as the cradle of Germanic tribes, as early as a 6th-century gloss to the Historia Ecclesiastica of Eusebius. In the 10th-century History of Armenia of Yovhannes Drasxanakertc’i (1.15) Ashkenaz was associated with Armenia, as it was occasionally in Jewish usage, where its denotation extended at times to Adiabene, Khazaria, Crimea and areas to the east. His contemporary Saadia Gaon identified Ashkenaz with the Saquliba or Slavic territories, and such usage covered also the lands of tribes neighboring the Slavs, and Eastern and Central Europe. …
Sometime in the early medieval period, the Jews of central and eastern Europe came to be called by this term. Conforming to the custom of designating areas of Jewish settlement with biblical names, Spain was denominated Sefarad (Obadiah 20), France was called Tsarefat (1 Kings 17:9), and Bohemia was called the Land of Canaan. By the high medieval period, Talmudic commentators like Rashi began to use Ashkenaz/Eretz Ashkenaz to designate Germany, earlier known as Loter, where, especially in the Rhineland communities of Speyer, Worms and Mainz, the most important Jewish communities arose. Rashi uses leshon Ashkenaz (Ashkenazi language) to describe German speech, and Byzantium and Syrian Jewish letters referred to the Crusaders as Ashkenazim. Given the close links between the Jewish communities of France and Germany following the Carolingian unification, the term Ashkenazi came to refer to both the Jews of medieval Germany and France.
In other words, the Ashkenazi and Sephardic Jews named themselves after their countries of residence, not their ancestors. Even if they were, there is no definite proof/opinion as to who the descendants of Ashkenaz are today. No proof, in other words, that they are Khazars. (The Khazarian king, Joseph, claimed that they descended from TOGARMAH, not Ashkenaz.) In light of all this, claiming that their name – “Ashkenazi Jews” – means they must come from Ashkenaz instead of Judah is like saying that “American Jews” must be American Indians. (It’s also like the Palestinians naming themselves after the Philistines, despite not being remotely related.)
This is the second major problem for the “Ashkenazi=Khazar” hypothesis: the utter lack of historical evidence. While there is some evidence that the Khazarian royal family – and perhaps some of the elite and population – converted to Judaism, a mass national conversion to Judaism – of the kind promoted by anti-Ashkenazis – finds no real basis in history. The following article from Haaretz puts it rather bluntly:
New study finds no evidence that Ashkenazi Jews are the descendants of Khazars, or that subjects in the medieval kingdom converted to Judaism en masse.
The claim that today’s Ashkenazi Jews are descended from Khazars who converted in the Middle Ages is a myth, according to new research by a Hebrew University historian.
The Khazar thesis gained global prominence when Prof. Shlomo Sand of Tel Aviv University published “The Invention of the Jewish People” in 2008. In that book, which became a best seller and was translated into several languages, Sand argued that the “Jewish people” is an invention, forged out of myths and fictitious “history” to justify Jewish ownership of the Land of Israel.
Now, another Israeli historian has challenged one of the foundations of Sand’s argument: his claim that Ashkenazi Jews are descended from the people of the Khazar kingdom, who in the eighth century converted en masse on the instruction of their king. In an article published this month in the journal “Jewish Social Studies,” Prof. Shaul Stampfer concluded that there is no evidence to support this assertion.
“Such a conversion, even though it’s a wonderful story, never happened,” Stampfer said.
Stampfer, an expert in Jewish history, analyzed material from various fields, but found no reliable source for the claim that the Khazars – a multiethnic kingdom that included Iranians, Turks, Slavs and Circassians – converted to Judaism. “There never was a conversion by the Khazar king or the Khazar elite,” he said. “The conversion of the Khazars is a myth with no factual basis.”
As a historian, he said he was surprised to discover how hard it is “to prove that something didn’t happen. Until now, most of my research has been aimed at discovering or clarifying what did happen in the past … It’s a much more difficult challenge to prove that something didn’t happen than to prove it did.”
That’s because the proof is based primarily on the absence of evidence rather than its presence – like the fact that an event as unprecedented as an entire kingdom’s conversion to Judaism merited no mention in contemporaneous sources. “The silence of so many sources about the Khazars’ Judaism is very suspicious,” Stampfer said. “The Byzantines, the geonim [Jewish religious leaders of the sixth to eleventh centuries], the sages of Egypt – none of them have a word about the Jewish Khazars.”
The research ended up taking him four years. “I thought I’d finish in two months, but I discovered that there was a huge amount of work. I had to check sources that aren’t in my field, and I consulted and got help from many people.”
Stampfer said his research had no political motives, though he recognizes that the topic is politically fraught. “It’s a really interesting historical question, but it has political implications,” he said. “As a historian, I’m naturally worried by the misuse of history. I think history should be removed from political discussions, but anyone who nevertheless wants to use history must at least present the correct facts. In this case, the facts are that the Khazars didn’t convert, the Jews aren’t descendants of the Khazars and the contemporary political problems between Israelis and Palestinians must be dealt with on the basis of current reality, not on the basis of a fictitious past.”
Sand had tied the Khazar issue directly to the Israeli-Palestinian conflict, telling Haaretz in 2008 that many Jews fear that wide acceptance of his thesis would undermine their “historic right to the land. The revelation that the Jews are not from Judea [ancient Israel] would ostensibly knock the legitimacy for our being here out from under us … There is a very deep fear that doubt will be cast on our right to exist.”
Stampfer believes the persistence of the Khazar conversion myth attests to researchers’ reluctance to abandon familiar paradigms. “Those who believed this story – and they are many – usually didn’t do so for malicious reasons,” he says. “I tell my students that the only thing I want them to remember from my classes is the need to investigate and ask – to investigate whether the arguments they hear are credible, reasonable and well-founded.”
Another article explains:
…the theory is absolutely without evidence. As any historian will tell you, generations of Jews, like generations of any people, leave historical traces behind them. These traces come in multiple forms. For starters, people leave behind them historical documents and archaeological data. Predictably, archaeologic evidence about the widespread existence of Jews in Khazaria is almost nonexistent. While a series of independent sources does testify to the existence in the 10th century of Jews in the Kingdom of Khazaria, and while some of these sources also indicate that the ruling elite of Khazaria embraced Judaism, the Khazarian state was destroyed by Russians during the 960s. In other words, we can be confident that Judaism was not particularly widespread in that kingdom.
The next historical record of Jews — in a few cities that today belong to western Ukraine and western Belarus — shows up in the 14th century, when Jews are regularly referred to in numerous documents.
One city in northwest Ukraine, Volodymyr-Volynskyi, does seem to have an uninterrupted presence of Jews from the 12th century. For example, in 1171 a Jewish merchant called Benjamin from that city lived in Cologne, and a Russian document refers to local Jews in 1288. Another Jewish source describes a circumcision ceremony in that city at the end of the 14th century. But it is only during the 16th century that references to Jews appear in large territories of Ukraine, Belarus and Lithuania, and even in the mid-16th century local communities were not populous. Historical documents also indicate that the earliest known Jewish communities in Poland were all situated in its westernmost part. 
Uh-huh. So, historically speaking, there is no reason to believe the Ashkenazim to be anything other than Jews.
What about linguistics?
LINGUISTICS AND ONOMASTICS
As the above-quoted article explains further:
This view is shared by all major Yiddish linguists — but not by Paul Wexler. Wexler believes there to be certain structural Turkic and Iranian elements “hidden” in Yiddish.
His methods rely heavily on fortuitous coincidences. And if you apply them more widely, you can link Yiddish to any language in the world.
It is simply bad linguistics. All words of Turkic origin came into Yiddish via the intermediary of East Slavic languages. It is the lexicon that keeps the actual traces of languages spoken by ancestors of Yiddish speakers. For that reason, in addition to Hebrew and Aramaic words, Yiddish has a small set of words whose roots come from Old French, Old Czech and Greek.
Some proponents of the Khazarian theory admit the German basis of Yiddish, but pretend that it was learned in Eastern Europe by “indigenous” Jewish masses from rabbis who came from the West and who introduced Yiddish as a “prestige” language.
But such a scenario can hardly be accepted. Only the cultural languages, Hebrew and Aramaic, were prestigious. During the 16th and 17th centuries, Yiddish brought from Central Europe became the first language for all Jews of Eastern Europe, a vernacular rather than a prestige object. Slavic idioms were used in that area by both the Christian majority and (during the previous period) by local Jews of heterogenous origins. Far from prestigious, Yiddish, understandable even for children, was used to teach students the prestigious language of Hebrew. We know that Yiddish wasn’t a prestige language, because girls, who were not taught languages in school, spoke it, too. The role of mothers in the transmission of the everyday language is by far more important than that of fathers.
In addition to history and linguistics, a third discipline can help us put to rest the Khazarian hypothesis: onomastics, or the study of proper names. Looking at names, both first names and surnames, gives us a sense of how a community saw itself, its language and its origins. And in the Jewish communities of Eastern Europe over the past six centuries, not a single Turkic name can be found in documents listing Jewish names. Even in documents from the 15th and 16th centuries dealing with Jews who lived in the territories of modern Ukraine and Belarus have no such names.
In the corpus of given names used by Jews of Eastern Europe during the last centuries, we find the same linguistic layers as in the lexicon of Yiddish. There are numerous Germanic and Hebrew names and some Aramaic names. There are also Greek names (Todres from Theodoros, Kalmen from Kalonymos), Old French names (Beyle, Bunem, Yentl), Old Czech names (Khlavne, Slave, Zlate), and Polish names (Basye, Tsile), and very few East Slavic names (Badane, Vikhne). There are no Turkic names.
According to Martin B. Richards, presently available genetic studies, including his own study on Ashkenazi maternal lineages, all refute the Khazar theory. The claim that Ashkenazis as a whole take their origin from Khazars has been widely criticized as there is no direct evidence to support it. Using four Jewish groups, one being Ashkenazi, Kopelman et al found no evidence to the Khazar theory. 
In 2000, the analysis of a report by Nicholas Wade named Y Chromosome Bears Witness to Story of the Jewish Diaspora
“provided genetic witness that these [Jewish] communities have, to a remarkable extent, retained their biological identity separate from their host populations, evidence of relatively little intermarriage or conversion into Judaism over the centuries…. The results accord with Jewish history and tradition and refute theories like those holding that Jewish communities consist mostly of converts from other faiths, or that they are descended from the Khazars, a medieval Turkish tribe that adopted Judaism.”
Many argue that genetic studies on Jewish populations have refuted any claims of significant Khazar lineage, and have shown that most ethnic Jews draw their roots from the Middle East. A genetic study led by Dr. Gil Atzmon found that European Jews were most closely related to Middle-Eastern Jews, Palestinians, Druze, and non-Jewish Southern Europeans — evidence inconsistent with Khazar/Slavic hypotheses. Another genetic study led by Doron Behar found that, despite admixture from local populations, autosomal genetic samples from the Ashkenazi Jews, Caucasian Jews, Middle Eastern Jews, North African Jews, and Sephardi Jews form a relatively tight genetic cluster which overlaps with Samaritans and Israeli Druze which is strongly indicative of common Levantine ancestry.
None of these studies of Ashkenazi Jews have detected evidence of a significant Central or East Asian genetic component which is present in other Turkic populations. The actual Khazars would likely have been assimilated by the Krymchaks (Crimean Jews) following the fall of Khazaria. Even so, the Krymchaks had a long history of assimilating other Jews who came to the Crimea, so their ancestry is still largely Levantine.
Livshits, Sokal and Kobylianskyt investigated the genetic affinities of Jewish populations. They concluded that Jewish populations are more like one another than they are to non-Jews and that pairs of Jewish populations from different locations are more alike than pairs of non-Jewish populations. They maintained that the most economical explanation of their findings is that the modern Jewish population throughout the world was derived from a common original gene pool which underwent few changes during the dispersion of the Jewish people. They also reported that it was highly likely that the common origin of the Jewish populations was more recent than that of the non-Jews.
Globally speaking, his [Elhaik’s] general method is applicable only in a context of families that remained for centuries in the same places (for example, in Sardinia) but certainly not for population groups characterized by geographic mobility. As one of my friends pointed out, if we apply his idea to Barack Obama, the former US president will be classified as “Libyan” just because Libya lies in the middle of a line that unites Kenya and the UK.
The origin and history of the Ashkenazi Jewish population have long been of great interest, and advances in high-throughput genetic analysis have recently provided a new approach for investigating these topics. We and others have argued on the basis of genome-wide data that the Ashkenazi Jewish population derives its ancestry from a combination of sources tracing to both Europe and the Middle East. It has been claimed, however, through a reanalysis of some of our data, that a large part of the ancestry of the Ashkenazi population originates with the Khazars, a Turkic-speaking group that lived to the north of the Caucasus region ~1,000 years ago. Because the Khazar population has left no obvious modern descendants that could enable a clear test for a contribution to Ashkenazi Jewish ancestry, the Khazar hypothesis has been difficult to examine using genetics. Furthermore, because only limited genetic data have been available from the Caucasus region, and because these data have been concentrated in populations that are genetically close to populations from the Middle East, the attribution of any signal of Ashkenazi-Caucasus genetic similarity to Khazar ancestry rather than shared ancestral Middle Eastern ancestry has been problematic. Here, through integration of genotypes from newly collected samples with data from several of our past studies, we have assembled the largest data set available to date for assessment of Ashkenazi Jewish genetic origins. This data set contains genome-wide single-nucleotide polymorphisms in 1,774 samples from 106 Jewish and non-Jewish populations that span the possible regions of potential Ashkenazi ancestry: Europe, the Middle East, and the region historically associated with the Khazar Khaganate. The data set includes 261 samples from 15 populations from the Caucasus region and the region directly to its north, samples that have not previously been included alongside Ashkenazi Jewish samples in genomic studies. Employing a variety of standard techniques for the analysis of population-genetic structure, we found that Ashkenazi Jews share the greatest genetic ancestry with other Jewish populations and, among non-Jewish populations, with groups from Europe and the Middle East. No particular similarity of Ashkenazi Jews to populations from the Caucasus is evident, particularly populations that most closely represent the Khazar region. Thus, analysis of Ashkenazi Jews together with a large sample from the region of the Khazar Khaganate corroborates the earlier results that Ashkenazi Jews derive their ancestry primarily from populations of the Middle East and Europe, that they possess considerable shared ancestry with other Jewish populations, and that there is no indication of a significant genetic contribution either from within or from north of the Caucasus region.
Plus, a recent genetic study found that some 75% of Jews originated in the Middle East, again refuting the claims of anti-Semites.
The Khazarian theory is very strongly linked to anti-Semitism, one of the first warning signs. Wikipedia explains:
United Kingdom and United States
Maurice Fishberg and Roland B. Dixon’s works were later exploited in racist and religious polemical literature, by [some] advocates of British Israelism, in both Britain and the United States. Particularly after the publication of Burton J. Hendrick ‘s The Jews in America (1923) it began to enjoy a vogue among advocates of immigration restrictions in the 1920s; racial theorists like Lothrop Stoddard; antisemitic conspiracy theorists like the Ku Klux Klan’s Hiram Wesley Evans; and anti-communist polemicists like John O. Beaty
In 1938, Ezra Pound, then strongly identifying with the Fascist regime of Benito Mussolini, sent a query to fellow poet Louis Zukofsky concerning the Khazars after someone had written to him claiming that the ancient Jews had died out and that modern Jews were of Khazar descent. He returned to the issue in 1955, apparently influenced by a book called Facts are Facts, which pushed the Jewish-Khazar descent theory, and which for Pound had dug up “a few savoury morsels”. The booklet in question, by a Roman Catholic convert from Rabbinic Judaism Benjamin H. Freedman was an anti-Semitic tirade written to David Goldstein after the latter had converted to Catholicism.
John O. Beaty was an antisemitic, McCarthyite professor of Old English at SMU, author of The Iron Curtain over America (Dallas 1952). According to him, “the Khazar Jews were responsible for all of America’s – and the world’s ills,” beginning with World War I. The book had little impact until the former Wall Street broker and oil tycoon J. Russell Maguire promoted it. A similar position was adopted by Wilmot Robertson, whose views influenced David Duke. The British author Douglas Reed has also been influential. In his work the Ashkenazi are false Jews, descendants of the Khazars.: 355
A number of different variants of the theory came to be exploited by the Christian Identity movement. The Christian Identity movement, which took shape from the 1940s to the 1970s, had its roots in British Israelism which had been planted on American evangelical soil in the late 19th century. By the 1960s the Khazar ancestry theory was an article of faith in the Christian Identity movement. The Christian Identity movement has associated two verses from the New Testament, Revelation 2:9 and 3:9 with the Khazars. Jeffrey Kaplan calls these two passages the corner stone of Identity theology. He also reports that Christian Identity literature makes selective references to the Babylonian Talmud, while the works of Francis Parker Yockey and Arthur Koestler work are raised almost to the status of Holy Writ.
Soviet Union and Russia
The theory was prominent in Soviet antisemitism, gaining a place in Soviet historiography. The theory influenced Soviet historians including Boris Rybakov, Mikhail Artamonov and Lev Gumilyov and was used to support soviet political theory.: Vii-Viii Artamonov argued that the Khazars had played an important role in the development of Rus’. A view that Rybakov disputed instead regarding the Khazar state as parasitic.: 260–261 Official Soviet views on the Khazars hardened after December 1951 when Pravda published a critical review of Artamonov’s work under the pen name P. Ivanov.: 313–314 Rybakov for his part denied that he was Ivanov.: 261 It has been speculated that Ivanov was in fact Stalin. In Ivanov’s review the Khazars were regarded as parasites and enemies.: 237 Ivanov’s views became the certified Soviet position.: 314
Lev Gumilyov’s theory of ethnogenesis draws heavily on the Khazars theory. For Gumilyov ethnicity was defined by stereotypical behavior which was linked to adaption to the terrain.: 121–122 Jews, he regarded as a parasitic, international urban class. The Jews had dominated the Khazars creating a chimera, subjecting Rus’ to the “Khazar Yoke.”: 358–359, 368
Since the 1970s the term Khazars has entered the Russian nationalist lexicon, it is used as a euphemism for Jews. Vadim V. Kozhinov theorized that the Khazar Yoke was more dangerous to Rus´ than the Tatar Yoke.: 90 The Khazars were imagined as a persistent danger to Rus’.: 359 After the dissolution of the Soviet Union the theory maintained a role in Russian antisemitism. Contemporary Russian anti-Semites continue to perpetuate the Khazar myth.: 355–356 Gumilyov and his students work remain popular in Russia.: 356 “Khazars” and “ethnic chimera” have become preferred terms for antisemitic Russian chauvinists.: 356
Aum Shinrikyo is a Japanese doomsday cult. The cult was active in Japan and Russia, with an estimated 10,000 and 30,000 followers respectively. The groups “Manual of Fear” used the Protocols of the Elders of Zion in addition to other anti-Semitic material. The manual claimed that the Jews are really Khazars intent on world domination. The Khazar theory has also become part of the Ascended Masters theology. Hatonn, an extraterrestrial, transmits messages including the complete text of The Protocols of the Elders of Zion. He identifies the authors of The Protocols as Khazars and speaks of false Zionist Jews who have usurped and controlled the true Jews.
In addition, the modern conspiracy theorist movement has been hijacked by anti-Semites (it’s now fashionable to blame Israel, the Jews, or “the Zionists” [codename for the Jews and Israelis] for literally EVERYTHING that goes wrong in the world; we’ve returned to the days from the Dark Ages and beyond when Jews are ludicrously the scapegoat for EVERYTHING). Many of these hijackers jump onto the Khazar theory, often railing against “the Khazarian bankers” – meaning Jewish bankers. Others (such as Reformation.org) try to identify them as the “synagogue of satan”. The lack of evidence doesn’t seem to matter. Then again, to anti-Semites (such as David Duke and Henry Makow), it never did.
The Ashkenazi Jews ARE JEWS. P.E.R.I.O.D.