Battle of Soissons: King Robert I of France is killed and King Charles the Simple is arrested by the supporters of Duke Rudolph of Burgundy.
The Battle of Soissons was fought on 15 June 923 between an alliance of Frankish insurgent nobles led by Robert I, elected king in an assembly the year prior, and an army composed of Lotharingians, Normans, and Carolingian forces under King Charles III's command. The battle took place at Soissons, near Aisne. Robert was killed, but his army won the war. Charles was imprisoned by Herbert II of Vermandois and held captive until his death in 929. Rudolph, Duke of Burgundy, Robert's son-in-law, succeeded him as ruler of West Francia.