At the outbreak of the Civil War he was concerned with a plan to admit the Royal forces to Hull, for which the Parliamentary governor, Sir John Hotham, ordered his arrest.Escaping the troops sent to seize him, he fled to Holland, but returned to England later the same year and was wounded at the Battle of Powick Bridge near Worcester.Imprisoned in Whitehall he escaped once more, according to his own account on the very day he was to have been executed; John Evelyn records in his Diary on 6 September 1651 that Dyve dined with him and related the story of his "leaping down out of a jakes two stories high into the Thames at high water, in the coldest of winter, and at night; so as by swimming he got to a boat that attended for him, though six musketeers guarded him."[3] Dyve then went to Ireland where he once more served with the Royal forces; in 1650 he published an account of events in that country during the previous two years.He lost much of his fortune through his loyalty to the Crown, but also in part due to heavy gambling: in 1668, the year before he died, Samuel Pepys called him disapprovingly "a great gamester".