Wimbledon, the world's oldest and most prestigious tennis tournament, began in London today. The All England Lawn Tennis Club is hosting the championship for the 125th time, since the first tournament which was held in 1877. The Men's defending champion is Spain's Rafael Nadal. In the Women's section, defending singles champion American Serena Williams is trying to achieve a hat-trick after winning the titles in 2009 and 2010. India's Sania Mirza will begin her campaign in the women's singles tomorrow.