Morton landed with Warwick at Dartmouth on the 13th of September 1470, but the battle of Tewkesbury finally shattered the Lancastrian hopes, and Morton made his peace with Edward IV., probably through the mediation of Archbishop Bourchier.
Morton no doubt impressed Lancastrian traditions upon Henry VII., but he cannot be credited with any great originality as a statesman, and Henry's policy was as much Yorkist as Lancastrian.
As an ecclesiastic Morton followed orthodox Lancastrian lines: in 1489 he obtained a papal bull enabling him to visit and reform the monasteries, and he proceeded with some vigour against the abuses in the abbey of St Albans.
It became a borough in 1319 by a charter of Edward II., which was confirmed in 1342 and 1378, and by each of the Lancastrian kings.
During the Wars of the Roses he showed his sympathy with the Lancastrian party after the defeat of Henry VI.