Which person was the tallest ever?

Wadlow was born in 1918 and grew rapidly because of an overactive pituitary gland, which produced too much growth hormone. By the age of 8 he was taller than his father, and he was still growing when he died in 1940, aged just 22. He wore shoes about 47 centimetres long and needed leg braces to walk. Known as the Gentle Giant, he toured with a circus and promoted a shoe company. The tallest living man today is Sultan Kösen of Turkey, at 2.51 metres.