when the plague struck fustat in 689 or 690, abd al-aziz moved his residence and seat of government about south of the city and founded hulwan. according to the 15th-century egyptian historian al-maqrizi, abd al-aziz had relocated due to flooding in fustat in 690 and chose the site of hulwan for his new capital because its elevation, above the banks of the nile, was higher than the river's flood line. the foundation of hulwan began a custom of establishing "satellite residence town[s]", which was "repeated countless times by later rulers in various regions of the islamic world", according to kubiak.