Colonel T E Jolys DSO (Tommy Jolys) is a retired army officer, organizer of the district firefighters, leader of men, hero of many wars (PM29). He is a near-contemporary of Maria Turner, probably a few years younger than her. He is aged about 55, since he is described reverting to the little boy of 50 years ago, a reference to the Tin Trumpet Incident (PM29). Hence he would have served in the First World War rather than the many wars ie the little colonial wars of Arthur Ransome's childhood.
He lives at the head of the lake, as Mrs Tyson says Before we'd get the word to the Colonel at head of the lake there'd be nowt left of our valley but ash and smoke (PP8).
He is a shortish, stout man but has a big, carrying voice. When he demonstrates a long blast on his coach-horn he blew ... on ... and on ... and on, and only gets very red though Dick thinks that He'll burst (PM26).