' s ▁construction ▁is ▁unknown , ▁although ▁it ▁was ▁likely ▁ere cted ▁after ▁ 1 1 5 3 ▁following ▁Am al ric ' s ▁capture ▁of ▁As cal on ▁to ▁the ▁north ▁from ▁the ▁F at im id ▁C ali ph ate . ▁As ▁described ▁by ▁William ▁of ▁Ty re , ▁the ▁fort ▁was ▁small , ▁tant um ▁sp at ium ▁int ra ▁se ▁contin ens ▁quantum ▁est ▁j act us ▁la pid is ▁( cont aining ▁inside ▁as ▁much ▁space ▁as ▁a ▁stone ' s ▁throw ) ▁and ▁square - sh aped ▁with ▁four ▁to wers , ▁one ▁of ▁which ▁was ▁larger ▁than ▁the ▁others . ▁Am al ric ▁used ▁Dar om ▁as ▁a ▁launch ing ▁point ▁for ▁several ▁un success ful ▁military ▁campaign s ▁against ▁F at im id ▁Egypt . ▁In ▁addition ▁to ▁its ▁role ▁as ▁a ▁front ier ▁fort ▁on ▁the ▁border ▁of ▁Egypt , ▁Dar om ▁also ▁served ▁as ▁an ▁administrative ▁center ▁charged ▁with ▁collect ing ▁tax es ▁from ▁the ▁southern ▁areas ▁of ▁the ▁kingdom ▁and ▁custom s ▁from ▁car av ans ▁and ▁travel ers ▁coming ▁from ▁Egypt . ▁It ▁was ▁de emed ▁a ▁permanent ▁threat ▁by ▁the ▁r ul ers ▁of ▁Egypt . ▁ ▁Not ▁long ▁after ▁its ▁construction , ▁a ▁small ▁sub urb ▁or ▁village ▁with ▁a ▁church ▁was ▁established ▁by ▁local ▁far mers ▁and ▁trad ers ▁just ▁outside ▁the ▁fort . ▁According ▁to ▁medieval ▁chron ic ler ▁William ▁of ▁Ty re , ▁" it ▁was ▁a ▁pleasant ▁spot ▁where ▁conditions ▁of ▁life ▁for ▁people ▁of