
Caudan is rural and one of the oldest parishes in the Dioceses of Vannes. Before some of its territory was handed over to Saint-Caradec Hennebont, it was also one of the largest. In 1909, it also lost its southern part when the municipality of Lanester was created. Bordered by the Blavet and Scorff estuaries, this area close to Lorient, was urbanized after the shipyards of the Compagnie des Indes de Lorient were set up around 1703 on the right bank of the Scorff. Its many workers increased the population of Caudan from 3,242 in 1793 to 9,646 in 1906, falling back to 2,487 in 1911 after the separation of the town of Lanester from that of Caudan.
In 1818, the village of Caudan comprised about forty buildings built along the roads leading in a star shape to the vast church square. It did not change much until after the war. The National road RN165 passes through the south of the town, where an industrial and commercial zone grew up, close to the urban centre of Lorient Lanester. Caudan experienced strong demographic growth, especially between 1968 and 1990, multiplying its population by 2.5 in the space of forty years, approaching 7,000 inhabitants today.
New populations come with the construction of areas that extended first to the south and then to the west along the traffic routes. The total housing stock has quadrupled since 1970. Residential districts, consisting of detached houses with gardens emerged, surrounding the villages closest to the town. Here, Restendrezen preserves an old sunken path and stone buildings, the remains of an old farmhouse.