I speak from the traditional knowledge in Islam.
Muhammad (peace be upon him and his family) and his Companions (may God be well pleased with them) are Arabs. Their origins are in Mecca and Madina. We know from the knowledge of the saints of Islam that Muhammad had 124 000 Companions, just as there were 124 000 prophets, and just as there are 124 000 saints of Islam. His closest Companion was Abu Bakr. They have known each other all their lives. Abu Bakr succeeded Muhammad on the throne of the kingdom of Islam.
At the battle of Badr, he stayed by Muhammad and kept the enemy away. His daughter is Aisha, the Mother of the Believers. His sons and daughters are heroes of the history of Islam. He died 2 years after Muhammad.
The Qur'an mentions him in many verses among which:
"But for such as fear the time when they will stand before (the Judgment Seat of) their Lord, there will be two Gardens"
Muhammad (peace be upon him and his family) said:
"If I were to take an intimate friend other than my Lord, I would have taken Abu Bakr."