Chilperic I was the king of Neustria (or Soissons) from 561 to his death. He was one of the sons of the Frankish king Clotaire I and Queen Aregund.
Immediately after the death of his father in 561, he endeavoured to take possession of the whole kingdom, seized the treasure amassed in the royal town of Berny and entered Paris. His brothers, however, compelled him to divide the kingdom with them, and Soissons, together with Amiens, Arras, Cambrai, Thérouanne, Tournai, and Boulogne fell to Chilperic's share. His eldest brother Charibert received Paris, the second eldest brother Guntram received Burgundy with its capital at Orléans, and Sigebert received Austrasia. On the death of Charibert in 567, his estates were augmented when the brothers divided Charibert's kingdom among themselves and agreed to share Paris.
Not long after his accession, however, he was at war with Sigebert, with whom he would long remain in a state of - at the very least - antipathy. Sigebert defeated him and marched to Soissons, where he defeated and imprisoned Chilperic's eldest son, Theudebert. The war flared in 567, at the death of Charibert. Chilperic immediately invaded Sigebert's new lands, but Sigebert defeated him. Chilperic later allied with Guntram against Sigebert (573), but Guntram changed sides and Chilperic again lost the war.
In September 584, while returning from a hunting expedition to his royal villa of Chelles, Chilperic was stabbed to death by an unknown assailant.