'Yan Salibiyya sun fara barin Constantinople a ƙarshen Afrilu 1097. Godfrey na Bouillon shine farkon wanda ya isa Nicaea, tare da Bohemond na Taranto, ɗan ɗan Bohemond Tancred, Raymond IV na Toulouse, da Robert II na Flanders suna biye da shi, tare da Peter the Hermit da wasu daga cikin wadanda suka tsira daga yakin Crusade na Jama'a, da kuma wani karamin sojojin
Byzantine karkashin Manuel Boutoumites.Sun isa ne a ranar 6 ga Mayu, da ƙarancin abinci, amma Bohemond ya shirya a kawo abinci ta ƙasa da ta ruwa.Tun daga ranar 14 ga watan Mayu ne suka sanya birnin suka yi wa birnin kawanya, inda suka tura dakarunsu zuwa sassa daban-daban na bangon, wanda ke da kariyar kariya da hasumiya 200.Bohemond ya yi zango a gefen arewa na birnin, Godfrey a kudu, da Raymond da Adhemar na Le Puy a ƙofar gabas.A ranar 16 ga watan Mayu masu tsaron bayan Turkiyya sun yi yunƙurin kai farmaki kan 'yan Salibiyya, amma
Turkawa sun sha kashi a fafatawar da suka yi da asarar mutane 200.Turkawa sun aike da sako zuwa ga Kilij Arslan suna rokonsa da ya dawo, kuma da ya fahimci karfin mayakan ‘yan Salibiyya sai ya juya baya da sauri.Sojojin da ke karkashin Raymond da Robert II na Flanders sun yi galaba a wani bangare na gaba a ranar 20 ga Mayu, kuma a ranar 21 ga Mayu sojojin 'yan Salibiyya sun yi galaba a kan Kilij a fafatawar da ta dauki tsawon dare.Asara ta yi yawa daga bangarorin biyu, amma a karshe Sarkin ya ja da baya duk da rokon da Turkawa Nicae suka yi.Sauran 'yan Salibiyya sun isa cikin sauran watan Mayu, tare da Robert Curthose da Stephen na Blois sun isa a farkon watan Yuni.A halin yanzu, Raymond da Adhemar sun gina wani babban injin kewaye, wanda aka naɗe shi har zuwa Hasumiyar Gonatas don haɗa masu tsaron kan bango yayin da masu hakar ma'adinai ke hako hasumiya daga ƙasa.Hasumiyar ta lalace amma babu wani ci gaba da aka samu.Sarkin Byzantine Alexios I ya zaɓi kada ya raka 'yan Salibiyya, amma ya bi bayansu ya yi sansani a Pelecanum kusa.Daga nan ne ya aika da jiragen ruwa, suna birgima a kan kasa, don taimaka wa ‘yan Salibiyya da suka killace tafkin Ascanius, wanda har zuwa wannan lokacin Turkawa suke amfani da shi wajen wadata Nicaea da abinci.Jiragen ruwan sun isa ne a ranar 17 ga watan Yuni, karkashin jagorancin Manuel Boutoumites.An kuma aika Janar Tatikios, tare da sojojin ƙafa 2,000.Alexios ya umurci Boutoumites da su yi shawarwari a asirce na mika wuya ga birnin ba tare da sanin 'yan Salibiyya ba.An umurci Tatikios da ya hada kai da ‘yan Salibiyya ya kai farmaki kan bangon kai tsaye, yayin da ‘yan Boutoum su kan yi kamar suna yin haka don a ga kamar Rumawa ne suka kwace birnin a yaki.An yi haka, kuma a ranar 19 ga watan Yuni Turkawa suka mika wuya ga Boutoumites.Sa’ad da ‘yan Salibiyya suka gano abin da Alexios ya yi, sai suka fusata sosai, domin sun yi begen su wawashe birnin don kuɗi da kuma kayayyaki.Boutoumites, duk da haka, an kira sunan dux na Nicaea kuma ya hana 'yan Salibiyya shiga cikin kungiyoyi fiye da maza 10 a lokaci guda.Boutoumites sun kuma kori Janar-Janar na Turkiyya, wadanda ya dauka a matsayin marasa amana.Iyalin Kilij Arslan sun tafi Konstantinoful kuma a ƙarshe an sake su ba tare da fansa ba.Alexios ya bai wa ’yan Salibiyya kuɗi, dawakai, da sauran kyaututtuka, amma ‘yan Salibiyya ba su ji daɗin hakan ba, suna ganin za su iya samun ma fiye da haka idan sun kama Nicaea da kansu.Boutoumites ba za su bar su su tafi ba har sai sun yi rantsuwa da Alexios na vassalage, idan ba su yi haka ba tukuna a Constantinople.Kamar yadda ya kasance a cikin Constantinople, Tancred da farko ya ƙi, amma a ƙarshe ya ba da izini.'Yan Salibiyya sun bar Nicaea a ranar 26 ga Yuni a cikin runduna biyu: Bohemond, Tancred, Robert II na Flanders, da Tatikios a cikin masu tsaron gida, da Godfrey, Baldwin na Boulogne, Stephen, da Hugh na Vermandois a baya.An umurci Tatikios da ya tabbatar da mayar da garuruwan da aka kama zuwa daular.Hankalinsu ya tashi sosai, kuma Istafanus ya rubuta wa matarsa Adela cewa suna tsammanin za su kasance a Urushalima nan da makonni biyar.