In pictures: 120 years of the modern Summer Olympic Games
It's been 120 years since the first modern Summer Olympic Games which took place in Athens in 1896.
The first modern Summer Olympic Games were held in the Panathenaic Stadium in Athens in 1896. In the first Games, only 14 countries took part in 43 events.
A Greek shepherd called Spyridon Louis won the first modern marathon event at the 1896 Games. He became a Greek sporting legend.
American athlete Jesse Owens won four gold medals at the Berlin Games in Germany in 1936. His achievement was particularly important because it was at the time when the racist leader of Germany, Adolf Hitler, had planned to show the world that Ayran people were better than other people. Jesse Owens proved him wrong and sealed his place in Olympic history.
At the 1968 Mexico City Games, US athletes Tommie Smith and John Carlos raised their fists and did not sing the national anthem on the winners' podium. They were protesting over the rights and treatment of black people in the USA.
US swimmer Michael Phelps has won the most Olympic gold medals of all time - with a total of 18. He also holds the record for winning the most golds at one Olympics, when he won eight at the 2008 Beijing Games.
In 2012, the Olympics came to London for the first time since 1948. Great Britain had a fantastic Games, with notable gold medals for Jess Ennis-Hill in the heptathlon, two for Laura Trott in cycling and two for Mo Farah in the 10000m and 5000m.
Women were allowed to compete in the Olympic Games from 1900 - but only in tennis, sailing, croquet, equestrianism and golf. The 2012 Games in London were the first in which women competed in every Olympic sport.