Partizan's supporters, known as Grobari (Serbian Cyrillic: Гробари, "Gravediggers or Undertakers"), were formed in 1970. The origin of the nickname itself is uncertain, but an accepted theory is that it was given by their biggest rivals, the Red Star fans, referring to club's mostly black colours which were similar to the uniforms of cemetery undertakers. The other theory says that the name arrives from the Partizan's stadium street name, Humska ("humka" meaning "grave mound"), in actuality named after medieval land of Hum. The first groups of organized Partizan supporters began to visit the JNA stadium in the late 1950s. Partizan's participation in the 1966 European Cup Final attracted much more fans to the stadium and it is considered to be the point when the organized fans moved to the south stand of the stadium, where they gather to this day. During the 1970s the Grobari started bringing fan equipment to the stadiums such as supporting scarves, signs, banners and flares. By the 1980s the Grobari were one of the four main fan groups in SFR Yugoslavia and began touring all Partizan's matches across the country and Europe. Because of their expressed hooliganism toward other clubs' supporters in those times, fans who represented the core of the Grobari firm were often called among themselves "Riot Squad". They were best known for their English style of supporting, which was mainly based on loud and continuous singing. By 2010, the Grobari consisted of three large groups: Grobari 1970, Zabranjeni and Južni Front.