Both Mostar clubs are among the oldest in the country. HŠK Zrinjski (, ) was formed in 1905 while FK Velež was formed in 1922. However, the clubs had vastly different histories. Zrinjski was a reasonably successful club in the first half of the century, but was banned by communist Yugoslav authorities for competing in the Prva HNL under Ustasha regime during World War II. At this point its records, along with those of other Croatian clubs, were destroyed. On the other hand, FK Velež thrived during the Yugoslav communist period, winning the Yugoslav Cup in 1981 and 1986.