Who is the oldest man in the world?

The longest unambiguously documented lifespan is that of Jeanne Calment of France (1875-1997) who was aged 122 years and 164 days at the time of her death. Jeanne Calment met Vincent Van Gogh when aged 14, and in 1988 this led to her, at age 113, becoming noticed by the media. Subsequent investigation found that her life was documented in the records of her native city of Arles, France beyond reasonable question. In fact, more evidence for the Calment case has been produced than for any other supercentenarian case, which makes her case a 'gold standard' among the 'oldest people' recordholders. This is contrasted with the now-disputed claim of age 120 for the oldest man ever, Shigechiyo Izumi. While recognized by Guinness, even the Japanese authorities have hinted that his age was not certain. This claim was accepted in 1978, but subsequent additional research (as early as 1984) has raised doubt as to whether he was wrongly conflated with a brother who died at a young age.