Perduellio
In the early days of Ancient Rome, perduellio was the term for the capital offense of high treason. It was set down plainly in the Law of the Twelve Tables as thus:
"The Law of the Twelve Tables orders that he who has stirred up an enemy or who has handed over a citizen to the enemy is to be punished capitally.” (Marcianus, D. 48, 4, 3) .