During his career Lennard worked alongside such actors as Sir Laurence Olivier and Anthony Hopkins and in 1966 he would have his first encounter with Sir David Jason in the play The Rivals. Fifteen years later both David and Lennard would become immortalised in television history as they starred in the now legendary sitcom Only Fools and Horses in which Lennard played the role of Grandad. He died suddenly of a heart attack in 1984.