The primary cause of the Great Schism in the Christian church, which formally occurred in 1054, was a culmination of theological, political, and cultural differences between the Western (Roman Catholic) and Eastern (Orthodox) churches. Key issues included disagreements over papal authority, the use of leavened versus unleavened bread in the Eucharist, and various liturgical practices. Tensions had been building for centuries, exacerbated by cultural divides and differing political allegiances. The schism led to the establishment of the Catholic Church in the West and the Orthodox Church in the East, fundamentally altering Christianity's landscape and its regions of influence.