 On his mother's side he was a direct descendant of General Wickremasinghe (Wicramasinghe Maha Senevi who was later poisoned by the King) who was the Army Commander of King Keerthi Sri Rajasinghe (1580–1593) of Seethawaka to whom former Sri Lankan Prime Minister Ranil Wickremasinghe also traces his roots.Abeyesundere was educated at St. Joseph's College, Colombo, where he excelled in his studies.He had the unique distinction of coming first in the entire British Commonwealth in English, Latin and Greek at both the Junior Cambridge Examination as well as the Senior Cambridge Examination and won a scholarship to University.