In 1506 John Russell was of service to Archduke Philip of Austria and Juana his wife (King and Queen of Castile) when they were shipwrecked off Weymouth, and escorted the royal couple to the English court in London. He was one of the most accomplished gentlemen of his time and so impressed them by his gracious manners that they praised him highly to King Henry VII. He became a Gentleman of the Privy Chamber to Henry VII in 1507 and to his son and successor Henry VIII in 1509, who employed him in various military and diplomatic missions during the War of the League of Cambrai. He was at the taking of Thérouanne and Tournai. He was knighted on 2 July 1522 after losing an eye at the taking of Morlaix in Brittany, and he witnessed the Battle of Pavia.