These acts in turn embroiled him, shortly after his accession, in a war with Venice.[4] Together with his son, John VII, who was crowned as co-emperor in 1376, there were now no less than four emperors and one Despot in Byzantium,all of them more or less pawns in the policies of the Ottomans and the Italian city-states.[2] Andronikos IV ruled until 1379, when John V and Manuel II escaped and fled to the court of Murad I.[2] After apparently agreeing to cede the virtually independent Byzantine exclave of Philadelphia to the Ottomans, John V was reestablished on the throne with the help of Venetian ships and Ottoman soldiers.[7]