Abū Bakr as- Siddīq ‘Abdallāh bin Abī Quhāfah (573 CE – 22 August 634 CE), popularly known as Abu Bakr  was a senior companion (Sahabi) and through his daughter Aisha the father in law of the Islamic prophet Muhammad. Abu Bakr became the first openly declared Muslim  outside Muhammad's family.  Abu Bakr served as a trusted advisor to Muhammad. During Muhammad's lifetime, he was involved in several campaigns and treaties.

Umar  also spelled Omar  (584 CE – 3 November 644 CE), was one of the most powerful and influential Muslim caliphs in history.He was a senior companion of the Prophet Muhammad. He succeeded Abu Bakr (632–634) as the second caliph of the Rashidun Caliphate on 23 August 634. He was an expert Muslim jurist known for his pious and just nature, which earned him the epithet Al-Farooq ("the one who distinguishes (between right and wrong)"). He is sometimes referred to as Umar I by certain historians of Islam, since a later Umayyad  caliph, Umar II, also bore that name.

Uthman ibn Affan also known in English by the Turkish and Persian rendering, Osman, (579–17 June 656), was a companion of the Islamic prophet Muhammad and the third of the Rashidun, or "Rightly Guided Caliphs." Born into a prominent Meccan clan, Banu Umayya of the Quraysh tribe, he played a major role in early Islamic history, succeeding Umar ibn al-Khattab who died in office at the age of 59/60 years as caliph at the age of 64/65 years (the second-oldest ruler).

Ali (15 September 601 – 29 January 661) was the cousin and son-in-law of Muhammad, the prophet of Islam. He ruled as the fourth caliph from 656 to 661, and was first Imam of shia Islam from 632 to 661.