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Thiers wall

Thiers wall is a engineering topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Thiers wall rather than just read about it. In short: The Thiers wall (French: Enceinte de Thiers) was the last of the defensive walls of Paris. It was an enclosure constructed between 1841 and 1846 and was proposed by the French prime minister Adolphe Thiers but was actually implemented by his successor, Marshal Soult.

Thiers wall — main illustration
Thiers wall — illustration

Key takeaways

  • Thiers wall belongs to engineering; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Thiers wall to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Thiers wall from memory before moving on to harder problems.

Reference excerpt

The Thiers wall (French: Enceinte de Thiers) was the last of the defensive walls of Paris. It was an enclosure constructed between 1841 and 1846 and was proposed by the French prime minister Adolphe Thiers but was actually implemented by his successor, Marshal Soult. The 33 kilometres (21 mi) long wall and ditch made a complete circuit around the city as it stood at the time of the July Monarchy. It was bombarded by the Prussian Army during the Franco-Prussian War, captured by government troops during the Paris Commune and refortified at the start of the First World War. However, by then it had become obsolete as a fortification and was a barrier to the expansion of the city. The area immediately outside of it, known as "the zone", had become a shanty town. The wall was demolished in the interwar period; its path today can be traced by the Boulevards of the Marshals which originally ran just behind the fortifications and by the Boulevard Périphérique which was later built just outside. A few remnants of the wall can still be seen.

Background

By the mid-16th century, Paris was defended by walls which had been built and rebuilt over the preceding centuries, but apart from the latest additions were largely obsolete for modern warfare and enclosed too small an area to contain the growing suburbs. In 1670, King Louis XIV ordered the demolition of all the walls surrounding Paris on the grounds that France was militarily secure and that a modern system of border fortifications had been constructed at great expense, and that like London and Madrid, Paris had become too large to fortify. Following the course of the demolished walls, the first boulevards were laid out, wide tree-lined avenues whose name is the French word for "bulwark". An ambitious scheme of fortification for Paris proposed in 1689 by France's leading military engineer, Marshal Sébastien Le Prestre de Vauban, was not proceeded with. Following the Battle of Paris in 1814, when the Coalition armies had captured the city after a single day's fighting, there was renewed political pressure for the capital to be fortified. A royal commission for the defence of the kingdom considered the issue between 1818 and 1820, finally recommending a detailed plan of defences in the following year, but it was never implemented.

Planning When Louis-Philippe was proclaimed king of the French in 1830, there was renewed interest in the issue. A further commission on the defence of the kingdom first met in 1836 and by May 1838 began to consider the defence of Paris. After much debate, it was decided that the capital should be fortified in two ways; by a continuous wall which could be manned by the National Guard and would prevent infiltration or a surprise attack, and further out from that, by a chain of detached forts manned by the regular field army, which could prevent an enemy from establishing positions from which they could bombard the city and create a line so long that it would be difficult for besiegers to enforce a tight blockade. A further point in favour of this dual approach was that regular troops would not come into close contact with the notoriously rebellious Parisians, which might lead to a loss of discipline.

Implementation

On 1 March 1840, Adolphe Thiers returned to office as prime minister and soon war threatened over the Oriental Crisis, when France found itself in opposition to Britain and Austria over events in Egypt. He was therefore amenable to an approach by the Duke of Orléans and François Chabaud-Latour to implement the commission's recommendations to fortify Paris. Chabaud-Latour was an army officer who had worked on the commission's plans and was also a deputy in the National Assembly. Thiers obtained the backing of his cabinet for the scheme while the deputies were away on holiday, but then found there was fierce resistance from the left, led by François Arago and Alphonse de Lamartine, who suspected that the government had ulterior political motives: that the fortifications, especially the detached forts, were intended to threaten the Parisians in case of a revolt against the monarchy. Other arguments suggested that by making Paris a fortress, it would make the city an irresistible objective for any invading army. Thiers was forced to resign over foreign policy in October, but his successor, Marshal Soult, was determined to press on with the plan. Debate began in the legislature in January 1841 and the necessary legislation was passed on 3 April. This legislation appropriated 140 million French francs for the work, including 17,970 million francs for land acquisition, 16,608 million francs for earthworks and 83,356 million francs for masonry. It was also necessary to clear an area in front of the fortifications to ensure that there was an unobstructed field of fire. Initially, an area known as a zone non aedificandi ("building-free zone") of 974 metres was envisaged, which would have been laid out as public parkland; however the final solution was a zone of 250 metres beyond the ditch on which it was forbidden to erect anything except a wooden fence. Although landowners whose property was confiscated for the actual fortifications were paid compensation, there was nothing for those whose property lay within the zone and was thus devalued.

Construction

The construction of the new works were overseen by Guillaume Dode de la Brunerie, the inspector-general of engineers and chairman of the fortifications committee. The fortifications not only included a continuous defensive wall or enceinte around the capital, but also a line of sixteen bastion forts lying between 2 and 5 kilometres from the wall. Although designed for all-round defence, these forts, such as Fort d'Issy, were not positioned so as to be able to support each other, unlike the polygonal forts being built by the Prussians at that time. The work was undertaken by military engineers and commercial contractors and used a workforce of 20,000 troops and civilians. The course of the works crossed through 13 suburbs and was completed in 1846.

Description

… excerpt ends here. Continue reading the full article.

Illustrations

Thiers wall: Map of Paris from 1911 showing Thiers fortifications surrounding the city
Map of Paris from 1911 showing Thiers fortifications surrounding the city
Thiers wall: The Thiers wall and the Porte de Versailles at the turn of the 20th century. On the right is the rampart and the stone scarp wall, on the left is the counterscarp and beyond that the sloping glacis, with the slums of the zone just visible in the background.
The Thiers wall and the Porte de Versailles at the turn of the 20th century. On the right is the rampart and the stone scarp wall, on the left is the counterscarp and beyond that the sloping glacis, with the slums of the zone just visible in the background.
Thiers wall: The triumphal entry into Paris of the monarchs of Austria, Russia and Prussia on 31 March 1814, an event which led to calls for the city to be refortified
The triumphal entry into Paris of the monarchs of Austria, Russia and Prussia on 31 March 1814, an event which led to calls for the city to be refortified
Thiers wall: Adolphe Thiers in 1840
Adolphe Thiers in 1840
Thiers wall: The Porte de Sceaux, about 1910
The Porte de Sceaux, about 1910

Worked examples

Example 1 — a first encounter with Thiers wall

Start with the simplest possible case. Write down what Thiers wall claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Thiers wall before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Thiers wall ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Thiers wall

In research
Thiers wall appears in engineering research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Thiers wall in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Thiers wall is common in secondary-school and first-year university syllabi. It links to neighbouring topics 19th-century fortifications, Boulevards in Paris, Buildings and structures completed in 1844, so understanding it makes those chapters shorter.
In everyday life
Look for Thiers wall outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Thiers wall in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Thiers wall means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Thiers wall out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Thiers wall in simple terms?

The Thiers wall (French: Enceinte de Thiers) was the last of the defensive walls of Paris. It was an enclosure constructed between 1841 and 1846 and was proposed by the French prime minister Adolphe Thiers but was actually implemented by his successor, Marshal Soult.

Why does Thiers wall matter?

Because it connects several engineering ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Thiers wall?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Thiers wall.

Tags

  • 19th-century fortifications
  • Boulevards in Paris
  • Buildings and structures completed in 1844
  • Buildings and structures demolished in the 20th century
  • City walls in France
  • Former buildings and structures in Paris
  • Fortifications of Paris
  • Geography of Paris
  • Military history of Paris

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