Wall of Thiers
Coordinates: 48°54′00″N 2°20′49″E / 48.89995°N 2.34695°E
The Thiers wall was the last of the defensive walls of Paris. It was an enclosure constructed between 1841 and 1844 under a law enacted by the government of the French prime minister, Adolphe Thiers. It covered 7,802 hectares (19,280 acres), along the "boulevards des Maréchaux" (Boulevards of the Marshals) of today. A sloping area outside the wall, called a glacis, extended outward from the Thiers wall to the location of today's Boulevard Périphérique. The wall was demolished in stages between 1919 and 1929.
Louis-Philippe, proclaimed king of the French in 1830, was convinced that the key to defence of France was to prevent Paris from falling too easily into the hands of foreign armies as happened during the Battle of Paris in 1814. So he conceived the project of building around the city an enclosure of walls that would make the city impregnable.
A first draft was presented to the Chamber of Deputies in early 1833 by Marshal Soult, Council President and Minister of War. It immediately sparked a fierce resistance from the left, whose speakers suspected, or pretended to suspect, that the government had ulterior political motives: that the fortifications were, in fact, designed not to defend France, but to threaten the Parisians in case they come to revolt against the monarchy.
...
Wikipedia