“Tossan” Henning came from a famous sports family. His father, Bernhard Henning, was the chairman of the Neptun swimming club and was a board member of the Swedish Swimming Federation from 1912-16. Henning was a versatile swimmer specializing in breaststroke. His first Olympic medal came in 1912 with a silver in the 400 m breaststroke. Despite illness, he managed to claim another two silver medals at Antwerpen in 1920, both behind his fellow countryman Håkan Malmström. Four years later in Paris, Henning competed in the 4 x 200 m relay, but was only active in the heats. He was a multiple Swedish champion in the 200 and 400 metre breaststrokes and won a total of 21 Swedish championships. In 1911 his 6:28.75 min was a world record for the 400 breast. Henning also won five national championships in lifesaving. He was inducted into the International Swimming Hall of Fame in 1992.