Thompson Cooper, Dictionary of National Biography… (1887)
“ CONSTABLE, Sir THOMAS HUGH CLIFFORD (1762–1823) , topographer and botanist, was the eldest son of Thomas Clifford (fourth son of Hugh, third Lord Clifford of Chudleigh) , and Barbara Aston, youngest daughter and coheiress of James, fifth lord Aston of Forfar. His parents being catholics sent him to be educated in the academy opened at Liège by the English ex-jesuits after their expulsion from Bruges (Gillow, Bibl. Dict. of the English Catholics, i. 656) ; and he continued his studies at the college of Navarre, in Paris, after which he travelled on foot over Switzerland. ”
