 Taking advantage of John III Vatatzes ' invasion of Rhodes , John launched a military expedition across the Bosphorus against the Empire of Nicaea in 1233 . His three @-@ to @-@ four @-@ month campaign " achieved little , or nothing " ; the Latins only seized Pegai , now Biga in Turkey . With John 's approval , two Franciscan and two Dominican friars wanted to mediate a truce between the Latin Empire and Nicaea in 1234 but it was never signed . In a letter describing their negotiations , the friars described John as a " pauper " abandoned by his mercenaries . 
