 He was elected emperor in 1229 as the senior co @-@ ruler ( with Baldwin II ) of the Latin Empire , and was crowned in Constantinople in 1231 . John III Vatatzes , Emperor of Nicaea , and Ivan Asen II of Bulgaria occupied the last Latin territories in <unk> and Asia Minor , besieging Constantinople in early 1235 . John directed the defence of his capital during the months @-@ long siege , with the besiegers withdrawing only after Geoffrey II of Achaea and united fleets from Italian towns defeated their fleet in <unk> . The following year , John died as a Franciscan friar . 
