Blair was actually born in Monkend at Croft-on-Tees into a family of sailors who had become mineowners. His great-grandfather, the 9th Earl of Dundonald, a Scottish aristocrat, lost nearly all the family fortune by ploughing it into his invention of coal tar which, he said, would waterproof ships to prevent rotting timbers – the British navy, though, preferred copper bottomed ships. The 9th Earl’s two sons, Thomas and Archibald, fought so heroically in the Mediterranean during the Napoleonic Wars that Napoleon nicknamed the oldest “Le Loup des Mers” – the Sea Wolf. The younger brother, Archibald, married Jane Mowbray of Sunderland, and they took up residence at Hetton Hall, at Hetton-le-Hole.