Dhatusena is the son of Sangha, the daughter of King Mahanama who ruled Anuradhapura from 410 to 432.

The country had been invaded in 433 by six Tamil leaders from South India, known as the six Dravidians.

They overthrew the Sri Lankan monarch and have ruled the country for the past twenty six years, during which time, Sinhalese leaders had abandoned Rajarata and fled to the Ruhuna principality in the south of the country.

Ruhuna is the base for resistance against the invading rulers.

Dhatusena had been raised by his uncle, a Buddhist monk named Mahanama.

The Pandyan invaders were searching for Dhatusena, and his uncle had ordained him as a Buddhist monk to disguise him.

Dhatusena later organizes a resistance movement against the Tamil invaders and leads a rebellion against them.

Dhatusena claimed the kingship of the country in 455.

By the time Dhatusena starts the rebellion, three of the six Pandayn invaders are already dead, and in the battles that occur during the rebellion, two more are killed.

The final battle takes place in 459, where the last king, Pithiya, is killed.

Having successfully defeated the Pandyan invaders, Dhatusena is crowned as the king of Sri Lanka in 459, taking Anuradhapura as his capital.