In Union, many of the popular leagues are international clubs level. For most of their history, they were split into Southern and Northern hemisphere leagues. Recently that shifted, and the South African teams joined the United Rugby Championship which is European (Ireland, Italy, Scotland, Wales, and before Top 14 became preferred, France). This was because, despite the historical significance, the time zone difference between the South African and Australia/New Zealand teams were too severe. Now South Africa is in the United Champinoship, they only play in a +/-2 hour difference in terms of time zone.