Byzantine-Genoese Trade Dispute

Timeline

1. 1333–1335Galata colony · ByzantineAfter capturing Mytilene (Lesbos), Genoa pushed further onto the high ground along the north shore of the Golden Horn, illegally adding walls and castles and eroding the colony's boundaries as set by the 1261 Treaty of Nymphaeum.
2. 1336Lesbos and Constantinople · GreeceAndronikos III recovered Lesbos from Genoese control and immediately ordered the demolition of the walls Galata had illegally built toward the hillside; sources show the order was only partially carried out, and Genoa continued to consolidate its trading base.
3. 1336Bosphorus Strait and Golden Horn · ByzantineGenoa long controlled the Galata customs house, with most profits from Black Sea and Aegean trade flowing into the colony while the Byzantine capital's customs revenue remained meager; the struggle over straits transit duties and trade monopolies ran through the 1330s and grew increasingly intense.