The Dornhorst Memorial Prize is named in honour of the late Mr. Frederick Dornhorst — a distinguished Ceylonese Barrister and King’s Advocate — remembered as one of Royal College’s most illustrious sons. All Royalists owe a debt of gratitude to this eminent figure whose legacy continues to inspire generations. The prize is awarded to a student who demonstrates excellence in academics, extracurricular and co-curricular activities, discipline, leadership and mainly popularity within college.

Thenuwan is best known as the Royal College Boxing Captain, where he claimed the coveted Best Boxer title at the 105th Stubbs Shield Inter-School Boxing Championship with a gold medal in the 56kg Flyweight category. He was awarded the prestigious Col. T.Y. Wright Challenge Cup for the Most Scientific Senior Boxer. He is also a Taipei City Cup gold medalist, representing Sri Lanka internationally.

He is also the Vice-Captain of the Royal College diving team and has earned medals in national-level diving competitions, showcasing a rare combination of skill and versatility. His dedication and technical skill have made him a notable athlete in the Sri Lankan sports arena. Furthermore, he was the vice captain of Marsh house in 2024 and the captain of Marsh house in 2025 when Marsh House won the Athletics Meet.

He served as a Junior Prefect and Senior Steward, highlighting his commitment to college.