|Born||23 April 1890|
|Died||3 August 1965 (aged 75)|
|Club||SK Neptun, Stockholm|
Gumpel was born in a rich family, and in 1906 was one of the founders and early sponsors of the Stockholm swimming club SK Neptun. He competed at the 1908 Olympics in the 200 metre breaststroke and at the 1912 and the 1920 Summer Olympics in water polo, winning a silver and a bronze medal in 1912 and 1920, respectively. He was later a board member of the Swedish Swimming Federation between 1919 and 1931.
Gumpel had a short relationship with Greta Garbo before she moved to Hollywood. They kept in touch as friends for the rest of their lives. She was a frequent guest of Gumpel's when visiting Sweden.
In 1912 Gumpel graduated with a degree in construction and founded the firm Gumpel & Bengtsson, which soon assumed a leading position in Sweden. During World War II Gumpel was involved in espionage with his friend Eric Erickson. With their help the allied powers obtained the exact locations of Germany's petroleum refineries and then bombed them. This event was reflected in a book and the 1962 film The Counterfeit Traitor.
- "Max Gumpel". Olympedia. Retrieved 12 April 2021.
- Max Gumpel. sports-reference.com
- Max Gumpel. Swedish Olympic Committee
- Garboforever. Garboforever. Retrieved on 1 February 2016.
- "Alexander Klein, 83; Wrote Spy Thriller (obituary)". New York Times. 24 August 2002. Retrieved 16 November 2007.
- ERIC ERICKSON, WARTIME SPY. Associated Press via New York Times (25 January 1983). Retrieved on 2016-02-01.
- Gumpels motorboat – Laila (1935). jsbab.se
- Max Gumpel at Olympics.com
- Max Gumpel at Olympic.org (archived)
- Max Gumpel at the Swedish Olympic Committee (in Swedish)
- Max Gumpel at Olympedia
- Max Gumpel at Olympics at Sports-Reference.com (archived)
- Max Gumpel at databaseOlympics.com (archived)
- Neptun 100år -in swedish
- Gumpels Skerry Cruiser – La Liberte (1934) -in swedish
- Gumpels amfibie car (1949) -in swedish
- Gumpels Chrysler 300 (1961)