When was the club that won the 1979-80 UEFA Cup founded?
1979–80 UEFA Cup: The 1979–80 UEFA Cup was won by Eintracht Frankfurt on away goals over Borussia Mönchengladbach. Borussia Mönchengladbach:  Founded in 1900, Borussia Mönchengladbach play in the Bundesliga, the top tier of the German football league system, making their first appearance in the league during the 1965–66 season.
1900