weeks of the war, he served on the staff of the RAF's Independent Air Force at its headquarters in Nancy, France. Following the disbanding of the Independent Air Force in November 1918, he remained on the Continent for two months as an RAF staff officer until posted back to Britain. He accompanied King Albert I of Belgium on his triumphal re-entry into Brussels on 22 November. Prince Albert qualified as an RAF pilot on 31 July 1919 and was promoted to squadron leader the following day. In October 1919, Albert went up to Trinity College, Cambridge, where he studied history, economics and civics for a year, with the historian R. V. Laurence as his "official mentor". On 4 June 1920 his father created him Duke of York, Earl of Inverness and Baron Killarney. He began to take on more royal duties. He represented his father and toured coal mines, factories, and railyards. Through such visits he acquired the nickname of the "Industrial Prince". His stammer, and his embarrassment over it, together with a tendency to shyness, caused him to appear less confident in public than his older brother, Edward. However, he was physically active and enjoyed playing tennis. He played at Wimbledon in the Men's Doubles with Louis Greig in 1926, losing in the first round. He developed an interest in working conditions, and was president of the Industrial Welfare Society. His series of annual summer camps for boys between 1921 and 1939 brought together boys from different social backgrounds. Marriage In a time when royalty were expected to marry fellow royalty, it was unusual that Albert had a great deal of freedom in choosing a prospective wife. An infatuation with the already-married Australian socialite Lady Loughborough came to an end in April 1920 when the King, with the promise of the dukedom of York, persuaded Albert to stop seeing her. That year, he met for the first time since childhood Lady Elizabeth Bowes-Lyon, the youngest daughter of the Earl and Countess of Strathmore. He became determined to marry her. Elizabeth rejected his proposal twice, in 1921 and 1922, reportedly because she was reluctant to make the sacrifices necessary to become a member of the royal family. In the words of Lady Strathmore, Albert would be "made or marred" by his choice of wife. After a protracted courtship, Elizabeth agreed to marry him. Albert and Elizabeth were married on 26