János Biri was born in Budapest on 21 July 1901 and died on 29 March 1983. He began at Kispest in his home city, moved to Italy with Padova in the mid-1920s for two seasons in the early Serie A, and played for Hungary at the 1924 Olympic Games before finishing his career with short spells in France and Portugal, retiring in 1936. He moved straight into coaching, winning the Campeonato do Porto with FC Porto in 1935/36 and taking them to second place in the league, before a brief period at Académico do Porto.

Benfica appointed him in 1939 and he stayed eight seasons, the longest unbroken tenure the club has given a coach in the modern era. His first match, on 17 September 1939, was a 5-2 defeat by Sporting; his last, on 2 July 1947, a 6-2 win over Boavista. In between he took charge of 273 matches and won 194 of them, a rate of 71 per cent that remains the highest of any Benfica coach with more than a hundred games. He won three national championships, in 1941/42, 1942/43 and 1944/45, three Taças de Portugal, in 1939/40, 1942/43 and 1943/44, and the Lisbon championship of 1939/40.

What distinguished him was his willingness to rebuild rather than protect an ageing title-winning team. He watched the club's youth sides himself and promoted from them without sentiment, treating the junior teams with the same seriousness as the first, and the pattern of solidity at the back and constant renewal in front of it carried Benfica through the war years. He coached another eleven clubs after leaving Lisbon and retired in 1966 after more than thirty years in the job.