▁the ▁threat . ▁Before ▁he ▁arrived , ▁news ▁reached ▁the ▁king ▁that ▁O do ▁had ▁gone ▁to ▁Pe ven sey ▁Castle , ▁which ▁was ▁under ▁the ▁control ▁of ▁Robert , ▁Count ▁of ▁Mort ain . ▁William ▁turned ▁away ▁from ▁Ro chester ▁and ▁seized ▁Pe ven sey . ▁The ▁captured ▁O do ▁was ▁forced ▁to ▁swe ar ▁to ▁hand ▁over ▁Ro chester ▁to ▁William ' s ▁men . ▁The ▁king ▁des patch ed ▁a ▁force ▁with ▁O do ▁in ▁to w ▁to ▁demand ▁Ro chester ' s ▁surrender . ▁Instead ▁of ▁yield ing , ▁the ▁g arrison ▁sal lied ▁and ▁captured ▁the ▁entire ▁party . ▁In ▁response ▁William ▁laid ▁sie ge ▁to ▁the ▁city ▁and ▁castle . ▁Contempor ary ▁chron ic ler ▁Order ic ▁V ital is ▁recorded ▁that ▁the ▁sie ge ▁began ▁in ▁May ▁ 1 0 8 8 . ▁Two ▁sie ge - cast les ▁were ▁built ▁to ▁cut ▁off ▁the ▁city ' s ▁supply ▁lines ▁and ▁to ▁protect ▁the ▁bes ie gers ▁from ▁sort ies . ▁Cond itions ▁within ▁the ▁city ▁were ▁dire : ▁disease ▁was ▁r amp ant , ▁ex ac erb ated ▁by ▁the ▁heat ▁and ▁f lies . ▁The ▁g arrison ▁ultimately ▁capit ulated ▁and ▁terms ▁were ▁agreed . ▁O do , ▁E ust ace , ▁Count ▁of ▁Bou log ne , ▁and ▁Robert ▁de ▁Belle me , ▁son ▁of ▁the ▁Earl ▁of ▁Sh rew s bury , ▁were ▁allowed ▁to ▁march ▁away ▁with ▁their ▁weapons ▁and ▁horses ▁but ▁their ▁est ates ▁in ▁England ▁were ▁conf isc ated