 Empress Matilda's invasion finally began at the end of the summer of 1139.Baldwin de Redvers crossed over from Normandy to Wareham in August in an initial attempt to capture a port to receive Matilda's invading army, but Stephen's forces forced him to retreat into the south-west.The following month, the Empress was invited by her stepmother, Queen Adeliza, to land at Arundel instead, and on 30 September Robert of Gloucester and Matilda arrived in England with a force of 140 knights.