Feyenoord became the first Dutch winner of the European Cup in 1970.
The Rotterdam club defeated Celtic 2–1 after extra time in the final at Milan's San Siro on 6 May 1970. Tommy Gemmell put Celtic ahead, but Rinus Israël equalised for Feyenoord before Ove Kindvall scored the decisive goal in the 117th minute. The victory made Feyenoord the first Dutch club to win Europe's premier club competition.
The club was commonly written as Feijenoord at the time. That spelling reflects the original Dutch form, while Feyenoord is the internationally familiar spelling used in the question and the club's official name since 1974. Both references identify the same Rotterdam side, so “Feyenoord” is the canonical quiz answer today.
The achievement also preceded a wider Dutch breakthrough in European football. Ajax had reached the 1969 final but lost to Milan, while PSV Eindhoven eventually won the competition in 1988. Feyenoord remain the only Dutch club to have won the European Cup just once, in 1970.