The early settlers of Paris no doubt thought that they had secured for themselves  a safe environment in which to found their city. the first fortifications around the Ile de la Cite and later to the north and south of the Seine may have been sufficient through to the end of the medieval period but come the era of gunpowder and heavy artillery and the presence of continental enemies to the north and east, particularly Germany, the natural advantages of the site became insignificant compared to the technological resources required  to defend the city. While Paris is protected by the loops of the Seine to the west, high ground overlooking the Bievre to the south, the line of the Marne to the south east and heights around the Forest of Montmorency to the north, natural defences to the north east are sparse and this unfortunately is the direction from which most of the city's post medieval assailants arrived.


In 1670 Louis XIV had demolished the existing walls and Paris remained an open city until the perceived threat from Germany lead to a series of commissions in the 1830s.  A plan of 1833 made a number of suggestions based primarily on the idea of fortifying the  Farmers General Wall, this had been a notional work designated primarily for tax purposes and creating, and creating a partial ring of detached works. By 1845 work on the inner Thiers Wall and most of the peripheral forts was complete. In 1870 the Franco-Prussian War broke out leading to a four month siege of the city. Following the 1871 Treaty of Versailles the German army withdrew and three years later France embarked on a huge programme of fortress building inspired by the doctrines of Sere de Rivieres. This included nearly 200 forts in strategic locations around the country several of them in the vicinity of the capital constituting the so called 'second ring' forts largely in place by 1890. Whilst the popular image was of Paris being surrounded by two concentric rings of forts the actual layout reflected closely the strategic and tactical opportunities of the local topography.

To examine more closely the defences including subsidiary works such as redoubts, batteries and military roads, it will be helpful to divide the works up according to the following strategic groupings:

Some useful material is available on line including: Les forts de la deuxieme ceinture autour de Paris Inventaire du devenir des 16 forts construits De 1870 a 1885

Le systeme Sere de Rivieres en Ile de France (les forts de seconde ceinture 1874-1881)

and especially the extraordinarily comprehensive Index de la Fortification Francaise 1874 - 1914

Excellent local mapping can be accessed at the web site of the L’Institut d’amenagement et d’urbanisme de la Region parisienne (IAURP)

A remarkable series of photographs taken of the 1840 enciente before the First World War by the photographer  E. Atget can be seen here: http://www.flickr.com/photos/18643384@N08/sets/72157607016164873/with/2808852973/