At which point did building city walls no longer become viable?

Jul 2015
89
Australia
From my understanding of the subject as the city's population grew so large and expanded out past the original walls (if any) it would have not been feasible to build a new city wall as it would have become too large and maybe indefensible.

I believe London has/had an ancient Roman wall but later larger city walls were not built as the city grew. Also I think Paris as late as WW1 had a city wall which encompassed most of the city but later was disused. At the time New York City was settled a city wall may have been useful but I can find no information on a New York City wall!

So at which point or under what circumstances did building a new city wall become not viable? Are there any present cities (of a reasonably large size) which still have city walls which could still be useful for defensive purposes even in the current age?
 

aggienation

Ad Honorem
Jul 2016
9,813
USA
The Vatican still makes really good use of its walls.

Walls are meant to keep someone out. Most often, enemy military forces. Maybe not forever, but long enough. How long could a wall stand up to 19th century artillery and mortars? How well could the large populations inside last in a siege?
 
  • Like
Reactions: David Vagamundo

Zip

Jan 2018
577
Comancheria
In the late 19th Century the increased range of cannon meant a city's defenses had to move farther out from the city, so far that a continuous wall would not be practical. Thus new fortifications were seperate but mutually supporting forts built in a ring outside the city. Such forts still exist at Antwerp, Verona, Ulm, Liege and many other cities; I look at them on Google Earth.

Existing city walls were then often destroyed and turned into spacious boulevards.


Ring forts outside Antwerp are circled.
CCA27937-10C5-45DE-9309-390721B4E7C2.jpeg
 
Last edited:

Chlodio

Forum Staff
Aug 2016
4,605
Dispargum
From my understanding of the subject as the city's population grew so large and expanded out past the original walls (if any) it would have not been feasible to build a new city wall as it would have become too large and maybe indefensible.

I believe London has/had an ancient Roman wall but later larger city walls were not built as the city grew. Also I think Paris as late as WW1 had a city wall which encompassed most of the city but later was disused. At the time New York City was settled a city wall may have been useful but I can find no information on a New York City wall!

So at which point or under what circumstances did building a new city wall become not viable? Are there any present cities (of a reasonably large size) which still have city walls which could still be useful for defensive purposes even in the current age?
New York City had a wall. The street that ran along the wall was called Wall Street which still exists. However, New York's wall was not a military fortification. It was built to keep cattle out of the town.

Walls really became obsolete when artillery advanced to the point where it could knock down thin walls. This was during the Late Middle Ages. Most of the walls that were knocked down by cannon fire were castle walls, not city walls, but it's the same principle. The initial response by military engineers was to build walls lower to the ground but thicker. Good examples can be found in any of the surviving star forts by Vauban or his followers. These thick walls usually took up too much space to be used around towns. Urban real estate is too valuable to waste on thick walls. While you could still find a few walled towns in the post-Medieval era, they were increasingly the exception rather than the rule. I agree with Zip about how 19th century urban defense replaced continuous walls with detached forts.
 
  • Like
Reactions: David Vagamundo
Sep 2017
771
United States
In the late 19th Century the increased range of cannon meant a city's defenses had to move farther out from the city, so far that a continuous wall would not be practical. Thus new fortifications were seperate but mutually supporting forts built in a ring outside the city. Such forts still exist at Antwerp, Verona, Ulm, Liege and many other cities; I look at them on Google Earth.

Existing city walls were then often destroyed and turned into spacious boulevards.
How'd the increased range make a difference for where walls needed to be?
 

stevev

Ad Honorem
Apr 2017
3,568
Las Vegas, NV USA
As late as the 1840's a new defensive city wall was built around Paris and lasted until after WW1.

Thiers wall - Wikipedia
The Fortress of Paris saved France (along with the earlier Russia invasion of Germany that drew off 2 corps from the German Western Offensive). The reduced German offensive was forced to pass to the north and east of Paris where its right flank was attacked from forces coming from the Fortress while was still fighting the main French force on its front (Battle of the Marne). The Germans retreated and began digging in for a long war of attrition they could not win.
 

Willempie

Ad Honorem
Jul 2015
5,498
Netherlands
I believe London has/had an ancient Roman wall but later larger city walls were not built as the city grew. Also I think Paris as late as WW1 had a city wall which encompassed most of the city but later was disused. At the time New York City was settled a city wall may have been useful but I can find no information on a New York City wall!
And Wall Street doesn't ring a bell?
 
Oct 2017
356
America ??
New York City had a wall. The street that ran along the wall was called Wall Street which still exists. However, New York's wall was not a military fortification. It was built to keep cattle out of the town.

Walls really became obsolete when artillery advanced to the point where it could knock down thin walls. This was during the Late Middle Ages. Most of the walls that were knocked down by cannon fire were castle walls, not city walls, but it's the same principle. The initial response by military engineers was to build walls lower to the ground but thicker. Good examples can be found in any of the surviving star forts by Vauban or his followers. These thick walls usually took up too much space to be used around towns. Urban real estate is too valuable to waste on thick walls. While you could still find a few walled towns in the post-Medieval era, they were increasingly the exception rather than the rule. I agree with Zip about how 19th century urban defense replaced continuous walls with detached forts.
What were the points of having walls in the first place?

And could you explain what continued of walls & urban defense after walls became obsolete with the advance of artillery, in the form of cannons I’m assuming, in the late Middle Ages, what time frame is that anyways? Did castles & states become more diplomatic & cooperative after that or something with the advance of the enlightenment?