PA Images
In their 120-year history, the games have played witness to the rise and fall of sporting heroes, political upheaval, and the greatest showcases of human ability.
But it hasn't been plain-sailing. They were suspended in 1916, 1940, and 1944 because of the outbreak of two world wars.
With the Rio games in full swing, we've delved into the archives to bring you one iconic image from each year of summer Olympic history.