information:classification, stylistic:style_transfer, structural:expansion
Early economics and concessions

Leopold could not meet the costs of running the Congo Free State. Desperately, he set in motion a system to maximize revenue. The first change was the introduction of the concept of terres vacantes, "vacant" land, which was any land that did not contain a habitation or a cultivated garden plot. All of this land (i.e., most of the country) was therefore deemed to belong to the state. Servants of the state (namely any men in Leopold's employ) were encouraged to exploit it.

Shortly after the Brussels Anti-Slavery Conference (1889–1890), Leopold issued a new decree mandating that Africans in a large part of the Free State could sell their harvested products (mostly ivory and rubber) only to the state. This law extended an earlier decree declaring that all "unoccupied" land belonged to the state. Any ivory or rubber collected from the state-owned land, the reasoning went, must belong to the state, thus creating a de facto state-controlled monopoly. Therefore, a large share of the local population could sell only to the state, which could set prices and thereby control the income the Congolese could receive for their work. For local elites, however, this system presented new opportunities, as the Free State and concession companies paid them with guns to tax their subjects in kind.

Trading companies began to lose out to the Free State government, which not only paid no taxes but also collected all the potential income. These companies were outraged by the restrictions on free trade, which the Berlin Act had so carefully protected years before. Their protests against the violation of free trade prompted Leopold to take another, less obvious tack to make money.

A decree in 1892 divided the terres vacantes into a domainal system that privatized extraction rights over rubber for the state in certain private domains, allowing Leopold to grant vast concessions to private companies. In other areas, private companies could continue to trade but were highly restricted and taxed. The domainal system enforced an in-kind tax on the Free State's Congolese subjects. As essential intermediaries, local rulers forced their men, women and children to collect rubber, ivory and foodstuffs. Depending on the power of local rulers, the Free State paid prices below the rising market prices. In October 1892, Leopold granted concessions to a number of companies. Each company was given a large amount of land in the Congo Free State on which to collect rubber and ivory for sale in Europe. These companies were allowed to detain Africans who did not work hard enough, to police their vast areas as they saw fit and to take all the products of the forest for themselves. In return for their concessions, these companies paid an annual dividend to the Free State. At the height of the rubber boom, from 1901 until 1906, these dividends also filled the royal coffers.

The Free Trade Zone in the Congo was open to entrepreneurs of any European nation, who were allowed to buy 10- and 15-year monopoly leases on anything of value: ivory from a district or the rubber concession, for example. The other zone—almost two-thirds of the Congo—became the Domaine Privé, the exclusive private property of the state.

In 1893, Leopold excised the most readily accessible 259,000 km (100,000 sq mi) portion of the Free Trade Zone and declared it to be the Domaine de la Couronne, literally, "fief of the crown". Rubber revenue went directly to Leopold who paid the Free State for the high costs of exploitation. The same rules applied as in the Domaine Privé. In 1896 global demand for rubber soared. From that year onwards, the Congolese rubber sector started to generate vast sums of money at an immense cost for the local population.