John Oxx has led the tributes to John Clarke, the former chief executive of the Irish National Stud and advisor to Mrs Tsui, who died on Thursday following a long illness. Clarke died peacefully in Blackrock Hospice in Dublin and, according to Oxx, will be remembered for leaving a "considerable mark" on the Irish National Stud's history. Oxx said, "I knew John well. He was the chief executive of the Irish National Stud for a long number of years. He enjoyed a long stint there, during which time the stud...