Hello!
The Western Schism lasted from 1378 to 1417 and was a split from within the Roman Catholic Church. Basically what happened was three popes thought that they were the "true" pope so eventually they split apart. The schism was ended by the Council of Constance on 1414 and lasted 4 years fro the debate to finally end on 1418.
I hope it helps!
These alliances that took place before World War 1 in a way started the war. For an example, Germany was in an alliance with Hungary and when they declared war against Serbia, Germany had to fight with them, and so on, finally creating World War 1. Within weeks, Germany declared war with other countries that declared war with others, creating a "domino effect" which just means that most countries just started fighting with one another, either because they declared war with them or because their allies did.
~Hope I helped!~
