Original Croatian name is HSK CONCORDIA (Hrvatski Sportski Klub Concordia).
CSC Concordia (Croatian Sports Club Concordia) was formed as a highschool football club in 1906 – Zagreb, Croatia. Until 1911, the club was called the Highschool football club. After the dissolution of FFSC, many of its players and employees join Concordia, contributing to the club’s strength and seriousness. Until the beginning of the First World War Concordia played many national and international matches. After the end of the war, Concordia merges with another high-school club, Viktorija, and gets the name Concordia-Viktorija, but the old name is soon returned as Viktorija once again becomes independent, the fourth ranking club in Zagreb (Građanski, Concordia, HAŠK, Viktorija). Before 1921, when the biggest (at the time) stadium in Zagreb was built, Concordia played on the high-school ground called Elipsa, in today’s Klaićeva street. The new stadium was built in Tratinska street. That is the ground in Kranjčevićeva street that has been used for nearly 70 years by FC Zagreb. In 1931, the stadium becomes the first in the region to get lighting. The first game for which it was used was the one between the teams of the cities of Zagreb and Madrid.