Dr Clarke is an Irish Ugandan who has lived in Uganda for 37 years. He first arrived during the peak of the HIV epidemic in the late 80s and set up a church hospital - Kiwoko Hospital, under the Church of Uganda. Kiwoko Hospital is known for its outstanding neonatal intensive care unit, its maternity service, nursing school and its lab technicians school.

Dr Clarke then moved to Kampala where he set up a private clinic in 1994. After the war he had witnessed the development of a Ugandan middle class and wished to set up a private hospital to serve their needs. He first developed a clinic and from that a small private hospital in Old Kampala. From there he purchased land in Namuwongo and built a purpose built hospital International Hospital Kampala (IHK). He also developed a network of clinics (IMCs) , a medical insurance company and a health science university. He founded the Uganda Healthcare Federation (UHF) to represent the private health sector and was chairman of the East African Healthcare Federation.

More recently he founded a commercial coffee farm, because coffee farming is a major driver to lift the rural poor out of poverty.