The Rashidun Caliphate was the first of the four major caliphates established after the death of the Islamic prophet Muhammad. It was ruled by the first four successive caliphs (successors) of Muhammad after his death in 632 CE. These caliphs are collectively known in Sunni Islam as the Rashidun, or "Rightly Guided" caliphs. This term is not used in Shia Islam, as Shia Muslims do not consider the rule of the first three caliphs legitimate.
The Rashidun Caliphate is characterized by a twenty-five-year period of rapid military expansion followed by a five-year period of internal strife. The Rashidun Army numbered more than 100,000 men at its peak.
By the 650s, in addition to the Arabian Peninsula, the caliphate had subjugated the Levant to the Transcaucasus in the north; North Africa from Egypt to present-day Tunisia in the west; and the Iranian Plateau to parts of Central Asia and South Asia in the east.