Henry William Carless Davis, 1911 Encyclopædia Britannica, Volume 15… (1911)
“ In spite of the incapacity which he displayed in this war, John was sent a little later to govern Ireland (1185) ; but he returned in a few months covered with disgrace, having alienated the loyal chiefs by his childish insolence and entirely failed to defend the settlers from the hostile septs. Remaining henceforth at his father’s side he was treated with the utmost indulgence. But he joined with his brother Richard and the French king Philip Augustus in the great conspiracy of 1189, and the discovery of his treason broke the heart of the old king (see Henry II.) . ”
