However he held hostage for a time his mother, Helena Kantakouzene, and her father, the former emperor John VI Kantakouzenos. However, in 1381 a treaty was signed in which allowed him to return. Later on the Venetians and Genoese ended their war and agreed to depopulate Tenedos and raze its fortifications, hence transforming it to a neutral territory.[7] This conflict further weakened the Byzantine Empire, which was surrounded by the massive and ever-expanding Ottoman Empire.