Jaffna, historical monarchy in northern Sri Lanka (Ceylon), populated largely by Tamil-speaking people of South Indian origin. It existed—with occasional interruptions—from the early 14th to the early 17th century.
Almost from the beginning of Sri Lanka’s recorded history, there had been sporadic invasions by peoples from South India. One of the best-known incidents was the victory in the 2nd century bce of the Sinhalese king Dutthagamani (or Dutugemunu) of Anuradhapura over the Tamil usurper Elara. From the 12th century the Tamils made increasing inroads into the northern part of Sri Lanka, and by the early 14th century they were sufficiently strong to establish a kingdom centred on the Jaffna Peninsula.
For much of the next three centuries the kingdom of Jaffna generally maintained its autonomy, the major exception being a period of subjugation (1450–77) by the Sinhalese Kotte kingdom. However, foreign incursions, notably by the Portuguese beginning in the early 16th century, had a destabilizing effect on all ruling polities on Sri Lanka, including Jaffna. Portuguese pressure increased considerably at the beginning of the 17th century, and Jaffna was finally conquered in 1619.