Thanthrimale goes a long way back in history, more than 2200 years. The sacred branch of the Bo Tree under which Lord Buddha attained Enlightenment, was brought by Sanghamitta Theraniya from India. They disembarked at Dambukola Patuna - close to present Keerimalai. The procession on its way to Anuradhapura was given a nights rest here, by a Brahmin.
One of the eight saplings of this Bo tree was planted here and is still present. This makes some claim that this Bo tree is older than the one at Anuradhapura - planted in the 2nd Century BC.
When the son of King Dutugemunu Prince Saliya married a woman of a low cast, they were banished by the father and they found refuge in Thanthrimale.