 At the professional level , meetings began to offer significant financial <unk> for all athletes in the 1990s in Europe with the creation of the " Golden Four " competition , comprising meetings in <unk> , Brussels , Berlin and Oslo . This expanded and received IAAF backing as the IAAF Golden League in 1998 , which was later supplemented by the branding of selected meetings worldwide as the IAAF World Athletics Tour . In 2010 , the Golden League idea was expanded globally as the IAAF Diamond League series and this now forms the top tier of professional one @-@ day track and field meetings . 
