The religion started in Makkah, Arabia in 7th Century CE, although God’s revelation and religion is much older, in that Muslims believe that the first prophet was Adam.
His final revelation though was given to Muhammad who was the seal of the prophets and the holy words (the Qur’an) revealed to him via the angel Gabriel where the final revelation of God (Allah) to mankind.
They recognise the other prophets such as Moses (Musa), Abraham (Ibrahim) and Jesus (Isa) but Muhammad is Allah’s final and most important prophet.
There are in total 28 prophets named in the Qur’an. “Islam” is an Arabic word that includes the concept of submitting to the will of God, thereby achieving peace and security.
To become a Muslim you need only utter the words, ‘There is no God but Allah and Muhammad is his prophet’, in front of witnesses and you have become a Muslim