Compromise of Caspe
1412 CE.
Shown on the map at 41.237°, -0.040°.
The 1412 Compromise of Caspe (Compromiso de Caspe in Spanish, Compromís de Casp in Catalan) was an act and resolution of parliamentary representatives of the constituent realms of the Crown of Aragon (the Kingdom of Aragon, Kingdom of Valencia, and Principality of Catalonia), meeting in Caspe, to resolve the interregnum following the death of King Martin of Aragon in 1410 without a legitimate heir. Succession through the male line, as ordained in the will of James I of Aragon should have gone to James II, Count of Urgell, however multiple others claimed the throne, which led to the "conclave" and compromise.
Text from the Wikipedia article Compromise of Caspe, licensed CC BY-SA 4.0.