Complex sentence: The Harfush dynasty (or Harfouche) was a dynasty that originated from the Khuza'a tribe, which helped, under the reign of Muhammad, in the conquest of Syria.
Split into simpler sentences: The Harfush dynasty (or Harfouche) was a dynasty that originated from the Khuza'a tribe. The Khuza'a tribe helped under the reign of Muhammad in the conquest of Syria.