Mongols are known in pop culture as being very anti-intellectual. This is backed up by the destruction of the Grand Library of Baghdad.

Was there any truth to this? Did the Mongols purposely kill all intellectuals?

Quite to the contrary, the Mongol Empire resulted in something popularly known as the "Pax Mongolica."

While many people were obviously killed, the unification of this territory meant that trade and ideas, both religious and scientific, easily spread from east to west and vice versa. They were known for killing the rulers/ruling class, not the intellectuals.

The Mongols had a habit of bringing scholars/artists/scientists/architects from one end of the empire to the other, so they did much to spread astronomy and math to China as an example, while bringing some of the eastern philosophies and religious ideas west.

That article can give you a good overview, and some of the positive effects of the Mongol conquests are debated pretty fiercely.

If you want to learn about some of the benefits of the Mongols, I recommend Genghis Khan and the Making of the Modern World by Jack Weatherford.

It's not the best textbook for a history class, but it does give the reader some things to think about when it comes to how the Mongols are perceived vs. their actual impact and policies. It is controversial though, so don't treat it as gospel.

The Mongols in Iran: Chingiz Khan to Uljaytu 1220-1309 is a good look at the net positive effect Mongol rule had on trade, but it's a very detailed look at the spread of currency and things of that sort, so it isn't exactly an entertaining read unless you are into that sort of thing.

In the early Mongolian period, under the rule of Genghis and his son Ögedei, Mongol conquests were rapid and bloody.They crushed anyone who dared oppose them and were very successful.This was fundamental for the largest land based empire to keep people from revolting. After Ögedei's reign, Chinese influence started to manifest itself on Kublai and his successors,Yuan dynasty.Kublai heeded the words of his grandfather Genghis' advosors 'This empire is won on horseback but will not be governed on horseback.He carried on large scale construction projects such as many temples and monasteries, the extension of the grand canal to Beijing and a capital city on Daidu(present day Beijing).He also patronized painting and theater.Records show that the Mongols funded astronomy and medicine throughout their empire. Perhaps most importantly, the Mongol empire inextricably linked Europe and Asia and ushered in an era of frequent and extended contacts between East and West. And once the Mongols had achieved relative stability and order in their newly acquired domains, they neither discouraged nor impeded relations with foreigners. Though they never abandoned their claims of universal rule, they were hospitable to foreign travelers, even those whose monarchs had not submitted to them.

The Mongols also expedited and encouraged travel in the sizable section of Asia that was under their rule, permitting European merchants, craftsmen, and envoys to journey as far as China for the first time. Asian goods reached Europe along the caravan trails (earlier known as the "Silk Roads"), and the ensuing European demand for these products eventually inspired the search for a sea route to Asia. Thus, it could be said that the Mongol invasions indirectly led to Europe's "Age of Exploration" in the 15th century.

To sum it all up, Mongols haven't DIRECTLY contributed to science, but substantially influenced the advancement of art and sciences and they certainly weren't anti-intellectual.

PS: I'm on mobile, will post sources tonight. Feel free to ask further questions

Edit: My source is; Columbia University, Asia for Educators,A New Look at Mongol Contributions found here: http://afe.easia.columbia.edu/mongols/history/history_a.htm

I would highly recommend giving 'Wrath of The Khans' by Dan Carlin a listen if you are interested in learning more about the early history of the Mongol Empire.