Ah I did not know that thanks
As for the Schism war. it came about during a period of chaos. Prior to the war, House Tytalus was corrupted by diabolists and then purged, but this brought just fear and suspicion to the Order. Intrigue, competition, and skirmishes escalated tensions and added to an atmosphere of distrust that began to dominate the Order. Differences of opinion led to frequent wizard's wars and raids against covenant resources.
The confusion thus bred led to an open conflagration as old feuds were sparked anew and recent disagreement grow into open hatred. Some houses became insular and retreated into hiding, while others became increasingly violent to deter potential attackers or to resolve personal grudges.The quaesitors* lost effective control as the magi all but stopped obeying their orders. Sides shifted continually and chaos threatened to consume the Order.
It was during this time that House Tremere fought many Wizards War against House Diedne. House Tremere is a highly militarized and orderly house;also a house with a strong ectomancy tradition. Tremere is a house which sought to make the order stronger with itself at the top. This contrasts with House Diedne who were the Descendants of Druids. House Diedne was an insular, secretive house; that mainly cared to be focus on their magic; they had a strong tradition of evocation.
This was a break down of politics due to the chaos of the time. No one was in the right and when the dust settled after House Diedne was renounced for being infernalists, and the rest of the order wanted to patch things up asap. Tremere and their allies lost about half if not more of their numbers fighting the wizards of Diedne.
*quaesitors: they are like wardens but more lawyeresqu and not so quick to just kill someone for breaking the code of hermes.