Answer
Chlothar I had three brothers: Childebert I, Clodomir, and Theuderic I. They were all sons of Clovis I, the founder of the Merovingian dynasty, and were instrumental in the expansion and consolidation of the Frankish kingdom. After Clovis's death in 511, the kingdom was divided among his four sons, with Chlothar receiving the northernmost part, centered around Soissons.