How did islam split into two groups

The major split in Islam is that between the majority Sunnis and the minority Shiites. The split goes back to events in the 7th century: After Mohammed's death in 632, leadership of the Islamic community passed to Abu Bakr as-Siddiq, one of Mohammed's closest companions.

To be honest i thinks its between the first answer and the third answer

The russian empire, the french third republic, and united kingdom of great britain and ireland