The Rashidun Caliphate (Arabic: الخلافة الراشدة al-Khilāfah ar-Rāshidah) is the collective term comprising the first four caliphs—the "Rightly Guided" or Rashidun caliphs (Arabic: الخلفاء الراشدون al-Khulafā’ ar-Rāshidūn)—in Islamic history and was founded after Muhammad's death in 632 (year 11 AH in the Islamic calendar). At its height, the Caliphate controlled a vast empire from the Arabian Peninsula and the Levant, to the Caucasus in the north, North Africa from Egypt to present-day Tunisia in the west, and the Iranian plateau to Central Asia in the east. It was the largest empire in history by land area up until that point.
After Muhammad's death in 632, the Medinan Ansar debated which of them should succeed him in running the affairs of the Muslims while Muhammad's household was busy with his burial. Umar and Abu Ubaidah ibn al-Jarrah pledged their loyalty to Abu Bakr, with the Ansar and the Banu Quraysh soon following suit. Abu Bakr thus became the first Khalīfatu Rasūli l-Lāh "successor of the Messenger of God", or caliph, and embarked on campaigns to propagate Islam. First he would have to subdue the Arabian tribes which had claimed that although they pledged allegiance to Muhammad and accepted Islam, they owed nothing to Abu Bakr. As a caliph, Abu Bakr was not a monarch and never claimed such a title; nor did any of his three successors. Rather, their election and leadership were based upon merit.
The Rashidun Caliphs (meaning "Rightly Guided", "Righteously Guided", "Righteous" Caliphs; Arabic: الخلفاء الراشدون al-Khulafāʾu ar-Rāshidūn), often simply called, collectively, "the Rashidun", is a term used in Sunni Islam to refer to the 30-year reign of the first four caliphs (successors) following the death of the Islamic prophet Muhammad, namely: Abu Bakr, Umar, Uthman ibn Affan and Ali of the Rashidun Caliphate, the first caliphate. The concept of "Rightly Guided Caliphs" originated with the later Abbasid Caliphate based in Baghdad. It is a reference to the Sunni imperative "Hold firmly to my example (sunnah) and that of the Rightly Guided Caliphs" (Ibn Majah, Abu Dawood).
The first four Caliphs who ruled after the death of Muhammad are often described as the "Khulafāʾ Rāshidūn". The Rashidun were either elected by a council (see the election of Uthman and Islamic democracy) or chosen based on the wishes of their predecessor. In the order of succession, the Rāshidūn were: