The most interesting historical eras / periods

[Kentucky 『 ＨＥＩＧＵＩ 』 James]

There are also a lot of theories about the collapse of the mongol empire(s). The ilkhanate (persia and anatolia) and the golden horde were very stable, with basically two borders separating Beijing and Byzantium and all the benefits that came from that. When those two states broke up it turned the near and middle east into a decentralised mess, where almost every state was a military junta and war was endemic -- hardly ideal for trade or innovation. Among other things it pushed trade out to sea and the region never recovered.
The Ottomans exacerbated the problem by allowing their economy to be exploited in the same silver-based mercantile scam that western europe pulled on the entire rest of the world.

Islam was also going through a bit of a political upheaval in the late 1300s. The great polymaths and scientists you got in al-andalus were becoming less common due to a lack of sponsors, and (sunni) Islam's new focus on theology put the golden age of arab and persian science to rest.

 

[Amman d Stazia]

European supremacy came from the coal and iron ore fields, and from the closure of the religious wars in a geographic divide of Protestant North and West, and a catholic South and East.
The age of exploration immediately preceded the early industrial revolution. Although the religious wars of the era inflicted huge destruction, they also channeled efforts into military advances, using the technologies and new ways of thinking that were arising.  (And I include here the idea that non-aristocrats could make significant contributions to anything.)
The Atlantic and North Sea coastal nations found themselves at peace (relatively) but with excellent military establishments, both land and naval, tactical and technological.

 

[havoc]

This man would like a word with you.

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Mr. Onion Hat