Islam
The Arabian peninsula.
The official religion is Islam.
In the 7th century A.D.
Muhammad started teaching Islam religion in the year of 610 A.D
In Arabia, in 610 when the last Prophet of Islam Hazrat Muhammad Mustafa (SAW) started preaching Islam to the people.
it's not a church it's a masjid .
All the Prophets preached Islam. Hazrat Adam (AS) was the first Prophet of Islam. The last Prophet of Islam was Hazrat Muhammad (SAW) who started preaching Islam in570 AD, in Kakka, Arabia.
The leader of Islam is prophet Muhammad (peace be upon him) and started in Mecca (or Makkah) in Saudi Arabia.
The present day country in which the last Prophet of Islam was born and preached Islam is called The kingdom of Saudi Arabia (KSA).
they were not Muslim to begin with but later converted to Islam.
Arabia _______________________________________ Islam began by start of universe creation and even before. Refer to question below.