 Complete the following phrase:  As national politics became increasingly divided during the 1450s, Oxford did not immediately take sides, although he was a member of the council while the Duke of York was Lord Protector in 145354 during Henry VIs period of mental breakdown, and on 28May 1454, together with 6 other peers and his brother, Sir Robert Vere, undertook to keep the seas for three years. In May 1455 he and the Duke of Norfolk both arrived a day too late to take part in the 