Hazrat Muhammad (PBUH) propagated Islam for more than 23 years and his companions (R.A.) thoroughly supported him in his struggle. These people stood by him in all sorts of circumstances whether favorable or adverse. Among, these people, four are especially important and they also succeeded Holy Prophet (PBUH) after his death and thus became the first four pious caliphs of Islam.
Hazrat Abu Bakr AL Sadique (R.A.):

• Hazrat Abu Bakr was the closest friend of Prophet Muhammad (PBUH)
• His real name was Abdullah Ibne Abi Quhafa
• He was the first person to embrace Islam
• If you pay some attention to learning Quran, you will find that he has been mentioned in Holy book (Quran 9:40)
• He was given the title of Sadique (truthful) for his unfaltering belief in whatever Holy Prophet (PBUH) said
• He was most generous of companions (R.A.) of Holy Prophet (PBUH)
• He became the first caliph after the death of Holy Prophet (PBUH)
• He ruled the Islamic world for more than two years
• He is buried besides Prophet Muhammad (PBUH) in Prophet’s (PBUH) mosques situated in Madinah
Hazrat Umar Ibne Khattab (R.A.):
• Hazrat Umar Ibne Khattab (R.A.) became the second caliph of Islam
• when Hazrat Muhammad (PBUH) became prophet, he was one of the very few persons in Makkah who were literate
• Hazrat Muhammad (PBUH) especially prayed for him so that he may embrace Islam
• He was 13 years younger than Holy Prophet (PBUH)
• He was given the title of Farooq because he could make right judgments about different situations
• He was courageous as well as tough
• He remained caliph for just more than ten years
• It was during his reign that Muslims conquered major Part of Iran and Rome including Palestine
• He was a great administrator and his laws are still practiced in the world with the name of Umar’s Law
• He was martyred by a slave whose name was Abu Lulo Feroz
• He is also buried besides Holy Prophet (PBUH) in Prophet’s (PBUH) Mosque
Hazrat Othman Bin Affan (R.A.):
• He became the fifth person to embrace Islam
• He was famous for his generosity and that is why he was given the title of Ghani
• His nickname was Dhu-Nnooryan (man having two lights) because he got married to two daughters of Hazrat Muhammad (PBUH)
• First one was Hazrat Ruqayya (R.A.) and when she passed away, he got married with other daughter of Prophet (PBUH) whose name was Hazrat Omme Kuthom (R.A.)
• He was very kind hearted and chivalrous
• He was the first person to prepare master copy of Holy Quran and that copy is still followed in all parts of Muslim world
• He remained caliph for almost 12 years
• He was martyred by miscreants for false allegations in his house in Madinah
• He is buried in Janat Al Baqi in Madinah
Hazrat Ali Ibne Abi Talab (R.A.)
• He was the first child to embrace Islam
• He was only ten years old when he became Muslim
• He was first cousin of Holy Prophet (PBUH)
• He was also the son in law of Holy Prophet (PBUH)
• He was very brave and for his bravery he was called Haider meaning a lion
• He was also very famous for his humality
• He was a learned person as well and therefore known as a “gateway to knowledge”
• He became the fourth caliph of Islam after the assassination of Hazrat Othman (R.A.)
• He ruled Muslim world for four years
• He shifted the capital of Islamic government from Madinah in Arabia to kofa in Iraq
• He was martyred by a Kharijite
• There are many speculations about where he is buried
• Some people say that his shrine is in Najaf, Iraq while others claim that he is buried in Blue Mosque in Mazar-e-Sharif, Afghanistan

Author's Bio: 

Anisa Fatima, is working with Qurantutor.com as project manager, and expert content writer, Quran Tutor providing services of Learning Quran, Quran tutoring, Quran teaching and Online Quran recitation to the people of all ages.