Complex sentence: Note that until 1860s, Romania, a predominantly Christian Orthodox country, used the Romanian Cyrillic alphabet, and that after switching to the Latin alphabet, it adopted the Orthodox version of the name over the Catholic Irene.
Split into simpler sentences: Note that until 1860s, Romania, a predominantly Christian Orthodox country, used the Romanian Cyrillic alphabet. After switching to the Latin alphabet, it was adopted in Romania the Orthodox version of the name over the Catholic Irene.