Sir Patrick Duncan was born on 21 December 1870 in Fortrie (Aberdeen-shire). Duncan first educated in Edinburgh, he entered Balliol College, Oxford, where he gained several distinctions. At the age of 23 he entered the Revenue Department at Somerset House, London, and was chosen as private secretary to Sir Alfred Milner, who brought him to South Africa in March 1901. Duncan was the senior member of Milner's famous 'Kindergarten', became Colonial Secretary in the Milner administration in the Transvaal, and in 1906 acted as Lieutenant-Governor of that colony. When the Transvaal received self-government in 1907 Duncan returned to England and was admitted to the bar at the Inner Temple, but came back to Johannesburg to practise as a barrister.