Maimonides
Emperor
I'm surprised nobody mentioned 1492 in Spain:
-The Inquisition was born.
-Columbus made his 1st voyage to the Americas.
-The last Muslims in Iberia were defeated.
-The large Jewish population of Spain was converted or expelled.
-Spain was united under a single monarchy.
Each of those points had a huge impact on world history. Taken together, 1492 Spain must be the biggest turning point during the OP's time period.
-The Inquisition was born.
-Columbus made his 1st voyage to the Americas.
-The last Muslims in Iberia were defeated.
-The large Jewish population of Spain was converted or expelled.
-Spain was united under a single monarchy.
Each of those points had a huge impact on world history. Taken together, 1492 Spain must be the biggest turning point during the OP's time period.
In more seriousness, Fuller and Creasy might have bibliographies to help.