The two biggest football clubs in Serbia - Crvena Zvezda (Red Star Belgrade) and Partizan - are based in the capital. Their stadiums are huge bowls of noise on match days, with thousands of fans singing and waving flags. Crvena Zvezda won the European Cup (now called the Champions League) in 1991.
Serbia's national team plays in the men's World Cup most times it is held. Their kit is red, blue and white - the colours of the Serbian flag - and they wear a double-headed eagle on the chest, an old symbol from a thousand years ago.
Serbian players are famous around the world. Tall, technical midfielders and skilful strikers play in top clubs across Europe. Many of them grew up kicking a worn-out ball around a concrete courtyard or a small village pitch before being spotted by a coach.
Watching football is a family event. Grandparents, parents and children watch the same matches, talk about the same players, and have very strong opinions about the same teams. Big matches can clear a Serbian street for 90 minutes - everyone is inside watching.