Complex sentence: Muhammad ibn Abdullah ibn Ziyad founded the Ziyadid dynasty in Tihama around 818 AD; the state stretched from Haly (In present-day Saudi Arabia) to Aden.
Split into simpler sentences: Muhammad ibn Abdullah ibn Ziyad founded the Ziyadid dynasty in Tihama around 818 AD. The state stretched from Haly (In present-day Saudi Arabia) to Aden.