The name
Cilaos comes from the
Malagasy word,
Tsilaosa (modern form:
tsy ilaozana), which means
the place one does not abandon. According to some historians , the word
Cilaos finds its origins in the name of a Malagasy slave named
Tsilaos who took refuge in this cirque. At the time, slaves were called "brown", whereas runaway
slaves were called "black-brown". The first inhabitants of the cirque of Cilaos were thus "black-browns" who believed themselves to be at the top of the world and completely safe. However, these first runaways were recaptured very quickly, tracked and hunted by well-organized and well-armed slaveholders. In these runaways' attempts to escape recapture, several were killed. It seems likely that these first runaways created the goat paths that climb most of the mountains on Réunion. After the death or recapture of these runaway slaves, the cirque of Cilaos likely became uninhabited once again for a while, since the first official record of its
settlement occurs only around 1850. In this year, a spa station was set up, and by 1866, there were 960 inhabitants. By 1900, the population had risen to 2500, and the 1982 census recorded 5629 inhabitants in the whole cirque. From 7 to 8 January 1966, 1,825mm (72 inches) of
rain fell in Cilaos in 24 hours, the
greatest amount of rain ever to fall in one day. The commune of Cilaos was created on 4 February 1965 when it seceded from the commune of
Saint-Louis. . ==Population==