About the year 1171 he was obliged, for the affairs of his diocese, to go over to England to see the king, Henry II, who was then at Canterbury. The Saint was received by the Benedictine monks of Christ Church with the greatest honour and respect. On the following day, as the holy archbishop was going to the altar to officiate, a maniac, who had heard much of his sanctity, and who was led on by the idea of making so holy a man another St. Thomas, struck him a violent blow on the head. All present concluded that he was mortally wounded; but the Saint came to himself, asked for some water, blessed it and having his wound washed with it, the blood was immediately stopped, and the Archbishop celebrated Mass.
In 1175 Henry II of England became offended with Roderic, the monarch of Ireland, and St.Lawrence undertook another journey to England to negotiate a reconciliation between them. Henry was so moved by his piety, charity and prudence that he granted him everything he asked and left the whole negotiation to his discretion. He died on 14 November 1180