The French attempted to create a colony there in the 18th century in conjunction with its settlement of some Caribbean islands, such as Guadeloupe and Saint-Domingue. During the Revolution, the National Convention voted to abolish slavery in February 1794, months after the rebelling slaves had already announced an abolition of slavery in Saint-Domingue. However, the 1794 decree was only implemented in Saint-Domingue, Guadeloupe and Guyane: it was a dead letter in Senegal, Mauritius and Reunion. Martinique had been conquered by the British, who maintained slavery there. Bill Marshall, Professor of Comparative Cultural Studies at the University of Stirling wrote of French Guiana's origins:  "Île du Diable" (Devil's Island) was the site of a small prison facility, part of a larger penal system by the same name, which consisted of prisons on three islands and three larger prisons on the mainland. This was operated from 1852 to 1953. In addition, in the late nineteenth century, France began requiring forced residencies by prisoners who survived their hard labour. A Portuguese-British naval squadron took French Guiana for the Portuguese Empire in 1809. It was returned to France with the signing of the Treaty of Paris in 1814. Though Portugal returned the region to France, it kept a military presence until 1817. After French Guiana had been established as a penal colony, officials sometimes used convicts to catch butterflies. The sentences of the convicts were often long, and the prospect of employment very weak, so the convicts caught butterflies to sell in the international market, both for scientific purposes as well as general collecting. A border dispute with Brazil arose in the late 19th century over a vast area of jungle, resulting in the short-lived, pro-French, independent state of Counani in the disputed territory. There was some fighting among settlers. The dispute was resolved largely in favour of Brazil by the arbitration of the Swiss government. The territory of Inini consisted of most of the interior of French Guiana when it was created in 1930. It was abolished in 1946, the year that French Guiana as a whole was formally established as an overseas department of France. During the 1970s, following the French withdrawal from Vietnam in the 1950s and warfare conducted in the region by the United States, France helped resettle thousands of Hmong refugees from Laos to French Guiana. In 1964, French president Charles de Gaulle decided to construct a space-travel base in French Guiana.