The Mabo Case was a test case in Queensland, Australia concerning native tribal rights to land usage, specifically involving the Meriam people (of which Eddie Mabo was a tribal member) and rights of tribal members to land on and use the Murray Islands, located in the Torres Strait.
The government attempted to derail the Mabo case by enacting the Queensland Coast Islands Declaratory Act of 1985, claiming that Queensland had all rights, claims and interest in the islands because of the annexation of the islands to Queensland in 1879.
In response to the Judgment on the Mabo Case issued in June, 1992, the Australian Parliament enacted the Native Title Act of 1993 that established a National Native Title Tribunal to adjudicate future similar disputes on tribal land usage.
The Mabo Case decision gave a boost to efforts for recognition of Aboriginal land rights.
The first reference outlines the details of the decision and its implications. A good summary of the case and judgment is fund in the second reference.