| Conflict: | Battle of La Rochelle |
| Partof: | the Hundred Years' War |
| Date: | December 30, 1419 |
| Place: | Coast and Port of La Rochelle |
| Coordinates: | 47.2667°N -1.3833°W |
| Result: | Castilian victory |
| Combatant1: | Crown of Castile |
| Combatant2: | County of Flanders[1] Hanseatic League |
| Commander1: | John II of Castile |
| Commander2: | Unknown |
| Casualties2: | 40 ships captured[2] |
| Campaignbox: |
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.