Roughly a year after seizing power in a coup, Mobutu moved to assert Congolese sovereignty over the country's vast mineral wealth, targeting the Belgian conglomerate Union Minière du Haut-Katanga. The nationalization was a defining early act of what would become a three-decade authoritarian rule, reshaping the relationship between the former colony and its onetime colonial master.
Congo's mineral wealth, especially the copper and cobalt of Katanga province, had been central to Belgian colonial exploitation since Leopold II's era. Union Minière had operated almost as a state within a state, running its own police, hospitals, and towns. When Mobutu moved against it, he was striking at the last major vestige of direct European economic control left over from colonial rule.
The nationalization fit into Mobutu's broader project of 'Zairianization,' though that formal policy came later. It won him popularity at home and cast him, for a time, as an anti-colonial nationalist, even as Western governments and mining interests fumed. In practice the seized assets were reorganized as Gécamines, a state-owned company that became both an economic engine and a vehicle for patronage and corruption.
Mobutu's later decades would be defined by kleptocracy and Cold War maneuvering, but this early confrontation with Union Minière showed the calculated boldness that let him outlast rivals and foreign pressure for so long.