A considerable nostalgia industry has evolved around the vanished French presence in Indochina (modern Vietnam, Cambodia and Laos). But how many remember Kwang Chow Wan (as it was known in English), the small territory on the coast of southern China that, for some decades, was part of French Indochina?

Situated on the Liaozhou Peninsula, roughly halfway between Hong Kong and Haiphong, Kuang Chou Wan (a popular French spelling) was leased by France from China in 1898. Now largely forgotten by history, the settlement was well known in Hong Kong before the Pacific war.

With a total land area of about 1,300 square kilometres, Kwang Chow Wan was somewhat larger than Hong Kong's New Territories. Its capital, centred on the Maxie estuary, was the port town of Zhanjiang (which the French renamed Fort Bayard). It remains the best natural harbour between Hong Kong and Indochina. Fort Bayard had a small French garrison and was directly administered from Hanoi.

The British lease in 1898 of the New Territories, along with Weihaiwei in Shantung, was driven by a number of "great power" considerations. The 1880s and 90s saw a dramatic resurgence of the age-old British rivalry with France. There were several cold war-style stand-offs and proxy conflicts; the most serious one, at Fashoda in the Sudan in 1898, brought the two powers to the brink of a world war.

The Kwang Chow Wan lease was seen at the time as a possible stepping stone to a French annexation of Hainan; southwest China had become a French "sphere of influence" by the 1890s, with a substantial Roman Catholic missionary presence and rail links between Nanning and Haiphong. Plans to extend the railway system to Kwang Chow Wan met with armed resistance from warlords, and the scheme was abandoned.

Other than Fort Bayard's strategic value, Kwang Chow Wan remained a backwater of French Indochina. An attractively restored church still stands but what little French architectural and cultural presence there once was has been obliterated.

Smuggling was a major economic activity in the area. In addition to opium (smuggled via French Indochina after the Hague Conventions on the international sale of opium to China came into force in 1917), aircraft destined for use by warlords were transported into China via the port. Even though the Americans had a ban on the sale of commercial aircraft until 1928, anyone with the resources to pay for them could purchase planes. Cantonese entrepreneurs bought surplus American aircraft in Manila (the Philippines was then a US colony).

Early in the Japanese occupation of Hong Kong, Kwang Chow Wan was an escape route from the captive British colony into Free China. In 1943, the Free French terminated the lease on the territory, though the move was academic as the Japanese were by then occupying Fort Bayard. The Nazi-collaborationist Vichy French government, in power in Indochina, then claimed it had assumed control.

Formally returned to China by France in 1946, in return for Chinese military withdrawal from northern Indochina, Kwang Chow Wan quickly returned to its tropical torpor.