Huns(Xiongnu), Turks(Tujue) and Mongols

a. Were Turks and Mongols descendants of Huns? Or were Huns just earlier Turks? What were the connections among Huns, Turks and Mongols?

b. Where were Huns and Turks originated from? Since both were first documented in Chinese sources (as Xiongnu and Tujue), were they Mongolian peoples gradually moving westwards? Were Huns survivors of Xiongnu (destroyed by Han) and Turks survivors of Tujue (destroyed by Tang)? I am just wondering had there been other Turkic peoples besides Tujue at that time.

c. Were Mongols mightier than Huns and Turks because they seemed to have accomplished what Huns and Turks failed to do (conquering Europe and China)?

d. (Skip this if alternate history is not your type) Guess what would be different if Turks were facing Song while Mongols facing Tang? Song after all, though the most populous and prosperous, was the militarily weakiest among all Chinese dynasties.

No, they were not their descendents. The Mongols descended from the Xianbei while the common ancestor of the Turkic peoples, as far as I could find, were the ancient Quanyi people.

The Xiongnu and Huns were Turkic.

Of course things change with the definition of the term "Turk". Today, it means a citizen of the Republic of Turkey. The Europeans started to use that term for the Oghuz people (who founded the Seljuks, Ottomans, Karakoyunlu, Akkoyunlu, Safavid, etc empires) in the 11th century AD. Starting from the 7th century, the Arabs, Byzantines and Iranians used "Turk" for a group of many related peoples such as the Tujue (G�k T�rks), Khazars, Qarluqs, Kyrgyz, Kypchaks, Uyghurs, Oghuz, etc... The Chinese useage of Tujue is limited to only one of these peoples, who are today known as the G�k T�rks.

OTOH, academicians use the terms "Turk" and "Turkic" with the meaning used by the Arabs, Byzantines and Iranians. Similar to the name "Greek", "Turk" was originially a name of a tribe/people, but it was later used for their relative peoples too. The name "Turk" didn't exist before 542 but there were clearly peoples whom we today classify as Turkic; such as the Xiongnu, Huns, Jiangun (Ancient Kyrgyz), Oghurs, Bulgars, Dingling, Gaoche-Tiele and others.

The Hunnic peoples, ie the Hongyi, Xunyu, Xianyun and Xiongnu, all appeared in Inner Mongolia as I could spot. The Huns of Europe, OTOH, are first seen in the Caspian Steppes. It's highly possible that they were formed from the remnants of Western and Northern Xiongnu fleeing westwards.

The earliest Turkic peoples also seem to have appeared in Inner Mongolia; however, the earliest Turkic culture, Okunevo (dated 2,000-1,500 BC), is located in the Southern Yenisei region.

The Tujue people appeared in the Southern Altais, but as I wrote above, there were Turkic peoples before them. The "Turks" of Turkey, Balkans, Middle East and Turkmenistan are all considered to be parts of the Oghuz people, who lived on the steppes north of Aral-Transoxiana during 9th-10th centuries. The Oghuz, like the Uyghurs, probably descended from the Tiele peoples, who descended from the Gaoche. The Gaoche were the same with Eastern Dingling, the Dingling and Jiangun were closely related peoples and they must have been descended from the Karasuk-Tagar cultures (the Dingling were associated with the "Red Di"). According to Chinese sources, the Quanyi were the common ancestor of the earliest Turkic peoples while archeologicially, they're traced to the Okunevo Culture.

Oh and btw, the Tang didn't destroy the Tujue Empire (that's a long story.)

Actually the Turkic peoples ruled parts of Central and Eastern Europe far longer than the Mongols did. Just look at the Huns, Bulgars, Sabars, Khazars, Pechenegs, Kypchaks, Oghuz and Ottomans  Btw, some minor dynasties in China were also of Turkic origin

d. (Skip this if alternate history is not your type) Guess what would be different if Turks were facing Song while Mongols facing Tang? Song after all, though the most populous and prosperous, was the militarily weakiest among all Chinese dynasties.

The Tujue (I use Tujue or G�k T�rk to differentiate them from other Turkic peoples) would have had lesser difficulties with their struggles against China. However, unlike the Jurchets, Khitans and Mongols, the Tujue, like the Xiongnu, didn't have major plans of conquering China partly and/or completely because their biggest trade partners was China itself.

Moreover, after Xiongnu was forced westwards by Han and Xianbei (encouraged by Han), some 500,000 stayed. They then call themselves Xianbei and integrated with their invaders (Xianbei). So quite some part of Mongol ancestors was, Turkic people.

The Western Tujue was defeated at 658, the On Oq replaced them a few decades later, the empire of the T�rgish (a branch of the On Oq) was finally overrun by the Qarluqs at 766. The Eastern Tujue were destroyed by Tang Taizong at 630, they re-gained their independence at 682 and their empire survived until 744, when finally it was destroyed by the Uyghurs, Qarluqs and Basm�ls.

Yes even Tang was heard to be (part) of Turkic origin

I would say Sinified Xianbei (Mongolic), not Turkic.

Hmm, highly possible

Of course the Xiongnu Federation was composed of Turkic, Mongolic, Tokharian, Iranic and other peoples; but the Xiongnu people itself and it's rulers were Turkic, as shown by the Chinese sources.

I don't think they were Iranic. They came from Gansu, a region near the Tarim Basin (land of the Tokharians). Besides, Greeks called them Tocharoi. The Yuezhi were more likely Tokharian.

Well, the Tujue were Turkic, but if you mean Anatolian Turks by "Turks", then yes, they were not the descendents of Tujue. The Turks of Turkey are Oghuz.

The �ngg�ts during the Mongol period were the descendents of Shatuo Tujue, these later contributed to the formation of the Kazaks. The Qarluqs were considered to be earlierly a part of the Tujue, and they got some descendents today I guess. If the Khazars and Pechenegs were parts of Tujue, then we can say there are still a few Tujue-remnants today.

I have questions here. Since everyone was saying that Xianbei was the direct ancestor of the Mongolian, so what about the Wuhuan tribe? I thought from the Wuhuan came Shiwei tribe and then from Shiwei came the Mongol or was Wuhuan considered part of the Xianbei tribe? And i heard people said that Xianbei was Tungusic people from Manchuria and was somehow related to Fuyu and Shuzhen tribes in Manchuria and Amur region, so which one was right then?

The Wuhuan were a branch of the Donghu people, not the Xianbei.

Btw, I thought Xianbei were the ancestors of the Khitans

I don't think they were Iranic. They came from Gansu, a region near the Tarim Basin (land of the Tokharians). Besides, Greeks called them Tocharoi. The Yuezhi were more likely Tokharian.

It seems to be impossible to resolve the entire structure and genealogical relationships between steppe tribes of various ethnicity. The tribes were relatively small, divided into clans and verticaly stratificated (warriors, priests etc. ) and involved in many cultural and political patterns. To a great deal cultural symetry between Turks and Iranians existed as well. Therefore I can only recall Sims-Williams who translated Rabatak inscription written perhaps in the first year of Kanishka reign in Bactria : "He issued(?) an edict(?) in Greek and then he put it into the Aryan language". This would point out an eastern iranian language of Kushans since Kanishka used bactrian for his inscription. However... Turks used Sogdian script and Praktrit was court language in Kroraina Kingdom...