The Rightly Guided Caliphs or The Righteous Caliphs (الخلفاء الراشدون al-Khulafā’u r-Rāshidūn) is a term used in Sunni Islam to refer to the first four Caliphs who established the Rashidun Caliphate. The concept of "Rightly Guided Caliphs" originated with the Abbasid Dynasty. It is a reference to the Sunni tradition, "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 quoted as the Khulafah Rashidun.
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 rashidun were:
Hasan ibn Ali was appointed as Caliph in 661 following the death of Ali and is also regarded as a righteous ruler by Sunni Muslims, although he was recognized by only half of the Islamic state and his rule was challenged and eventually ended by the Governor of Syria, Muawiyah ibn Abi Sufyan.
The Rashidun Caliphate (Arabic: الخلافة الراشدية al-khilāfat ar-Rāshidīyah), (c. 632-661) comprising the first four caliphs in Islam's history, was founded after Muhammad's death in 632 (Year 10 A.H. in the Islamic calendar). At its height, the Caliphate extended from the Arabian Peninsula, to the Levant, Caucasus and North Africa in the west, to the Iranian highlands and Central Asia in the east. At its greatest extent it was one of the largest empires in history. It is also known as the Patriarchal Caliphate.
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 (a Quraish) and Abu Ubaidah ibn al-Jarrah pledged their loyalty to Abu Bakr, with the Ansar and the Quraish soon following suit. Abu Bakr thus became the first Khalifa Rasul Allah (Successor of the Messenger of God), and embarked on campaigns to propagate Islam. First, though, he would have to subdue the Arabian tribes which had gone back on their oaths of allegiance to Islam and the Islamic community. As a Khalifa or Caliph he was not a monarch and never claimed such a title nor did his three successors do so.