Short answer
After the Prophet ﷺ died in 632 CE, four of his closest companions led the Muslim community in turn: Abu Bakr, 'Umar, 'Uthman and 'Ali. Sunnis call them the Rightly Guided Caliphs (al-Khulafa' ar-Rashidun).
The fuller answer
Abu Bakr held the community together after the Prophet's death and had the Quran collected. 'Umar led during the great expansion, set up courts, a state treasury and pensions. 'Uthman unified the written copy of the Quran. 'Ali was the Prophet's cousin and son-in-law, and led during a period of civil strife.
Their rule lasted about 30 years. Later caliphates, the Umayyads, Abbasids and the Ottomans, were dynasties and were not all seen as 'rightly guided' by scholars. The caliphate ended in 1924 with its abolition in Türkiye.
This answer follows the mainstream Sunni understanding and is general learning, not a fatwa. Where Muslims differ, the answer says so. Have a question of your own? Write to us.