The Comrades Marathon is the world’s largest and oldest ultra-marathon. It is an annual ultra-marathon run in the KwaZulu-Natal province of South Africa between the cities of Durban and Pietermaritzburg.  The start of the marathon alternates between the two cities each year and is around 89km long.

The Comrades Marathon attracts up to 25,000 runners from around the world each year and has been run every year with the exception of the World War 2 years.

The first Comrades Marathon was run on 24 May 1921.