Kammala wannan jumla: A watan Fabrairun 1071, Joscelin ya jagoranci ƙoƙari na ƙarshe don sauƙaƙe
Siege na Bari, wanda Robert Guiscard ya fara a watan Agusta 1068 bayan ya murkushe tawayen Apulian. A cewar Amatus, Joscelin yana dauke da zinariya da sauran abubuwa masu daraja don cin hanci da kewaye. Jirgin ruwansa na jirgi ashirin ya tashi daga Dyrrhachium da niyyar gudanar da toshewar Norman na Bari. An gano shi da dare ta hanyar fitilu biyu a kan jirgin ruwan Joscelin, rundunar sojojin Roger I na Sicily ta kama shi kuma ta ci nasara a cikin wani yanayi mai ban mamaki na yakin da aka yi a cikin teku da dare. An kama jirgin ruwan Joscelin a cikin aikin kuma an nutsar da wani jirgi. Amatus ya rubuta jiragen ruwa tara da aka kama gaba daya. Abin da ba a nutsar ko kama ba ya shiga cikin tashar jiragen ruwa na Bari. Wannan shi ne nasarar farko na Norman a cikin Bahar Rum. A cewar William na Apulia, "tseren Norman har zuwa wannan lokacin bai san komai ba game da yaƙin teku. Amma ta hanyar dawowa da nasara sun kara karfin shugaban su... " Bayan shan kashi na tawagar taimako, Bari ya mika wuya a watan Afrilu 1071. A cewar Geoffrey Malaterra, Joscelin yana da "tufafi mai ban mamaki a cikin salon Girka" a lokacin da aka kama shi kuma don haka aka gabatar da shi a gaban sojojin da ke kewaye da shi.