The naval Battle of La Rochelle of 1419 took place between a Castilian and an allied Flemish-Hanseatic fleet.
[3][4] The Castillian victory resulted in their naval supremacy in the Bay of Biscay.
but it also led to a protracted conflict with Flanders and the Hanseatic League, which ended in 1443 with further commercial concessions to Castile.
[5] The battle was notable for the use of guns by the Castilian fleet.