Genoa had acquired trading and settlement rights in the Crimea in the Treaty of Nymphaeum in 1261 with Michael VIII Paleologos in return for the assistance in the defeat of the Latin state which emerged after the Sack of Constantinople during the Fourth Crusade and in the re-establishment of the Byzantine Empire in Constantinople. Genoa had establishments all around the Black Sea in the 14th century and held Trebizond with its alum mines. They made agreements with the Cumanian Khanate that predated the Mongol Invasion. This made sense as they could carry trade to Italy from the eastern end of the silk road. Venice and Pizza also were deeply and competitively involved in this area, but Venice had more strength in the Mediterranean, as it held Cyprus. The Black Death followed the Mongols and seriously reduced the population of Constantinople. Both Genoa and Venice assisted in the defense of Constantinople against the forces of  Sultan Mehmed II, doomed though it turned out to be.  

"It is not necessary to have hope in order to persevere."