Obituary: Sir Denis Thatcher Denis Thatcher's motto: "Always present, never there" Often seen but rarely heard, Denis Thatcher was a loyal supporter, and occasionally a shrewd adviser, to the woman he called "the Boss".As Margaret Thatcher confessed in 1985, on the 10th anniversary of becoming leader of the Conservative Party, "I couldn't have done it without Denis." He met the young Margaret Roberts when she was the Tory parliamentary candidate for Dartford in 1951. They married the same year. His money, made in the oil business, helped sustain her career and twins Mark and Carol were born two years...