In October 1919, Albert went up to Trinity College, Cambridge, where he studied history, economics and civics for a year. On 4 June 1920, he was created 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 his tendency to shyness, caused him to appear much less impressive 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.

Answer this question, if possible (if impossible, reply "unanswerable"): In what year did Louis Greig begin playing tennis?
unanswerable