The split between the Eastern Church and the Western Church became known as

the Great Divergence of 1054.

the Great Schism of 1054.

the Great Orthodoxy of 1054.

the Great Patriarchy of 1054.

The correct answer is that the split between the Eastern Church and the Western Church became known as the Great Schism of 1054. This is a split that has lasted right up until the modern day, with the churches still separated. They are now referred to as the Eastern Orthodox and the Roman Catholic Churches.