One of two remaining World War II survivors and Britain's most senior citizen became the world's oldest man Friday when the Japanese titleholder died in his sleep at the age of 113.

Brighton resident Henry Allingham, who turned 113 on June 6, took over the place of Tomoji Tanabe of Miyakonojo City in the Guinness Book of World Records' category of oldest man.

Tanabe, who turned 113 on Sept. 18, left a son and daughter-in-law at his deathbed. He had eight children, 25 grandchildren, 53 great grandchildren and six great-great-grandchildren, according to Telegraph.

Born in Clapton, East London in 1896, Allingham enlisted as a seaplane mechanic in 1915 when his mother died. After the war, he worked at Ford and retired in 1961. He was married for 50 years and has a great-great-great-grandchild.

Allingham said his secret to longevity is "to look after yourself and always know your limitations," according to Times Online.