Novak Djokovic, (born May 22, 1987, Belgrade, Yugoslavia [now in Serbia]), Serbian tennis player who was one of the game’s premier performers in the early 21st century, when he won 11 Grand Slam titles.

Djokovic took up tennis at age four and quickly ascended the junior ranks. Despite the hardships that came with growing up in the war-torn Serbia of the 1990s, he became Europe’s top-ranked 14-and-under player and later the number one 16-and-under player on the continent before turning professional in 2003. Djokovic entered the top 100 of the Association of Tennis Professionals (ATP) at age 18, and in July 2006 he won his first ATP event. After advancing to the semifinals at both the 2007 French Open and Wimbledon, he reached the finals of that year’s U.S. Open but lost in straight sets to Roger Federer. Djokovic’s hot play continued into 2008 as he won the first Grand Slam tournament of the year, the Australian Open, becoming the first Serbian man to win one of tennis’s four most prestigious singles championships.

Djokovic’s progress plateaued for almost three years, as he won just 10 ATP men’s singles tournaments and reached only one Grand Slam final (the 2010 U.S. Open) between February 2008 and the end of 2010. His fortunes turned in December 2010 when he led the Serbian Davis Cup team to the country’s first Davis Cup title. His Davis Cup victories marked the beginning of a 43-match winning steak—the third longest such streak in the Open era (since 1968)—which included a second Australian Open title in January 2011. Djokovic’s remarkable streak ended with a French Open semifinal loss to Federer, but his strong play helped him rise to the number one world ranking shortly after he defeated Rafael Nadal to capture the 2011 Wimbledon championship. Djokovic later defeated Nadal in the U.S. Open final to claim his third Grand Slam title of the year.

At the Australian Open in 2012, he again bested Nadal, winning a five-set thriller that lasted nearly six hours. The two met for the fourth consecutive Grand Slam final at the 2012 French Open, where Djokovic lost to Nadal in four sets. In 2013 Djokovic defeated Andy Murray to win his fourth Australian Open title, and he captured another Wimbledon championship the following year when he beat Federer in a dramatic five-set final. He again beat Murray to capture his fifth career Australian Open in 2015, which made Djokovic the all-time leader in Australian Open men’s singles championships during the Open era. After a loss in the 2015 French Open final, the top-ranked Djokovic bested Federer to win his third Wimbledon championship. He continued his hot play at the U.S. Open, beating Federer in the final to capture his 10th career Grand Slam title. Djokovic ran his winning streak in Grand Slam matches to 21 when he beat Murray in straight sets in the final of the 2016 Australian Open.