Southwestern Australia has a long dynamic Precambrian history of crustal fragmentation and aggregation by continental collision and accretion. This interpretation contrasts with the widely held belief that most of Australia was part of a Proterozoic supercontinent in which all tectonic, magmatic, and metamorphic activity was intracontinental. The Pilbara and Yilgarn cratons are two quite different fragments of Archean continental crust that collided to form the Capricorn orogen between 2000 and 1600 Ma. The Albany-Fraser orogen formed along the southern margin of the Yilgarn craton during another major continental collision at 1300 to 1100 Ma. Rifting removed the northeastern part of these combined cratons and orogens between 1100 and 700 Ma. Subsequent continental collision along this rifted margin formed the Paterson orogen at 700 to 600 Ma. Therefore, the assembly of this considerable part of Gondwana may not have been completed until about 600 Ma.