Crocea Mors was the name given to Julius Caesar

Julius Caesar

Gaius Julius Caesar was a Roman general and statesman and a distinguished writer of Latin prose. He played a critical role in the gradual transformation of the Roman Republic into the Roman Empire....

's sword, according to the legends presented by Geoffrey of Monmouth

Geoffrey of Monmouth

Geoffrey of Monmouth was a cleric and one of the major figures in the development of British historiography and the popularity of tales of King Arthur...

. In Middle Welsh

Middle Welsh language

Middle Welsh is the label attached to the Welsh language of the 12th to 14th centuries, of which much more remains than for any earlier period. This form of Welsh developed from Old Welsh....

 versions, it is called Angau Coch ("Red Death") or Agheu Glas ("Grey Death").

The British prince Nennius

Nennius of Britain

Nennius is a prince of Britain at the time of Julius Caesar's invasions of Britain in Geoffrey of Monmouth's legendary History of the Kings of Britain . In Middle Welsh versions of Geoffrey's Historia he is called Nynniaw....

acquired it when, during single combat with Caesar, it got stuck in his shield. It killed everyone Nennius struck with it. Nennius died fifteen days after the battle of a head wound inflicted by Caesar, and the sword was buried with him.