Quran 9:29 instructs Muslims to fight and subjugate other people under Islam:
"Fight those who do not believe in Allah or in the latter day and who do not forbid what Allah and His Messenger have forbidden and who do not adopt Islam, (even if they are) of the People of the Book - [fight] until they humbly pay the Jizyah and have been subdued." - Quran 9:29
"His Messenger" refers to Muhammad, while "People of the Book" refers to Jews and Christians.
When Muslims conquer a new land, its surviving inhabitants, including Jews and Christians, are to be given a choice to either "adopt Islam" or "pay the Jizyah," which is an annual fine for not adopting Islam. Either choice leads to living under and obeying Sharia law. Those who refuse both choices are to be slain.