| Cassivellaunus | |
|---|---|
| King of the Catuvellauni | |
 A representation of Cassivellaunus, New York Public Library | |
| Predecessor | Unknown |
| Successor | Tasciovanus |
| Born | England |
| Died | England |
| Burial | Unknown (In legend: York) |
| Occupation | Chief commander of the British resistance during Caesar's second invasion of Britain |
Cassivellaunus was a historical British military leader who led the defence against Julius Caesar's second expedition to Britain in 54 BC. He led an alliance of tribes against Roman forces, but eventually surrendered after his location was revealed to Julius Caesar by defeated Britons.
Cassivellaunus made an impact on the British consciousness. He appears in British legend as Cassibelanus, one of Geoffrey of Monmouth's kings of the Britons, and in the Mabinogi, Brut y Brenhinedd and the Welsh Triads as Caswallawn, son of Beli Mawr.