Real Sociedad and Athletic Club will contest the Copa del Rey final for the first time in history on April 18 at the Estadio de La Cartuja in Seville.
The two Basque rivals have never met in the competition's showpiece before, although there have been three previous all-Basque finals.
The first of those came in 1910 when Athletic beat Vasconia Sporting Club in San Sebastian.
Athletic disputed the second all-Basque final too, losing to Racing Club de Irun - now known as Real Union - in 1913.
Irun were back in the final 14 years later, then as Real Union, and beat Arenas Club de Getxo.
This year, Athletic will play their 40th Copa final while Real Sociedad have made it to the final hurdle six times before.
La Real have lost five of their six finals, beating Atletico Madrid on the only time they didn't come up against Barcelona in it.
Basque finals
1910 Athletic-Vasconia Sporting Club
1913 Racing de Irun-Athletic
1927 Real Union-Arenas
Athletic's finals
Year Venue Champion Runner-up Result
2015 Barcelona Barcelona Athletic 1-3
2012 Madrid Barcelona Athletic 3-0
2009 Valencia Barcelona Athletic 4-1
1985 Madrid Atletico Athletic 2-1
1984 Madrid Athletic Barcelona 1-0
1977 Madrid Real Betis Athletic 2-2 (pen)
1973 Madrid Athletic Castellon 2-0
1969 Madrid Athletic Elche 1-0
1967 Madrid Valencia Athletic 2-1
1966 Madrid Real Zaragoza Athletic 2-0
1958 Madrid Athletic Real Madrid 2-0
1956 Madrid Athletic Atlético 2-1
1955 Madrid Athletic Sevilla 1-0
1953 Madrid Barcelona Athletic 2-1
1950 Madrid Athletic Real Valladolid 4-1
1949 Madrid Valencia Athletic 1-0
1945 Barcelona Athletic Valencia 3-2
1944 Barcelona Athletic Valencia 2-0
1943 Madrid Athletic Real Madrid 1-0
1942 Madrid Barcelona Athletic 4-3
1933 Barcelona Athletic Real Madrid 2-1
1932 Madrid Athletic Barcelona 1-0
1931 Madrid Athletic Real Betis 3-1
1930 Barcelona Athletic Real Madrid 3-2
1923 Barcelona Athletic Europa de Barcelona 1-0
1921 Bilbao Athletic Atletico 4-1
1920 Gijón Barcelona Athletic 2-0
1916 Barcelona Athletic Real Madrid 4-0
1915 Irún Athletic RCD Espanyol de Barcelona 5-0
1914 Irún Athletic RCD Espanyol de Barcelona 2-1
1913 Madrid Racing de Irun Athletic 1-0
1911 Bilbao Athletic RCD Espanyol 3-1
1910 San Sebastián Athletic Vasconia 1-0
1907 Madrid Real Madrid Vizcaya de Bilbao 1-0
1906 Madrid Real Madrid Athletic 4-1
1905 Madrid Real Madrid Athletic 1-0
1904 Madrid Athletic Club Español de Madrid (didn't show up)
1903 Madrid Athletic Real Madrid 3-2
1902 Madrid Vizcaya de Bilbao Barcelona 2-1
La Real's finals
Year Venue Champion Runner-up Result
1988 Madrid Barcelona Real Sociedad 1-0
1987 Zaragoza Real Sociedad Atletico 2-2 (p)
1951 Madrid Barcelona Real Sociedad 3-0
1928 Santander Barcelona Real Sociedad 3-1
1913 Barcelona Barcelona Real Sociedad 2-1
Source: m.allfootballapp.com