These families held their fief in vassalage from a suzerain. Lower Egypt came under Assyrian vassalage but proved unruly, unsuccessfully rebelling against the Assyrians. He conquered most of Albania and forced the remaining northern Albanian lords into vassalage. This practice would develop into the system of vassalage and feudalism in the Middle Ages. Edward and Harold were then able to impose vassalage on some Welsh princes. Babylon was occupied, and Babylonia reduced to vassalage. The king of Kongo also held several kingdoms in at least nominal vassalage. The Mughals placed the northern part of Arakan under its administration and vassalage. Moldavia finally returned to Ottoman vassalage in 1621. The settlers also viewed the treaties as committing the Natives to a form of vassalage. Babylon was invaded and sacked and Nabonassar reduced to vassalage. Ostoja led a war against the Republic of Dubrovnik, a Hungarian vassalage. He then demanded that Lazar proclaim his vassalage and pay tribute. Then was a brief period of vassalage to Burma until Naresuan proclaimed independence in 1584. A complicated system of rivalries and vassalage existed.