Fortifications are
military constructions
and
buildings designed for
defense in
warfare and
military bases. Humans have
constructed defensive works for many thousands of years, in a
variety of increasingly complex designs. The term is derived from
the
Latin fortis ("strong") and
facere ("to make").
Nomenclature
Many military installations are known as
forts,
although they are not always fortified. Larger forts may class as
fortresses, smaller ones formerly often bore the
name of
fortalices. The word fortification can
also refer to the practice of improving an area's defense with
defensive works.
City walls are
fortifications but not necessarily called fortresses.
The art of setting out a military camp or constructing a
fortification traditionally classifies as
castramentation, since the time of the
Roman legions. The
art/
science of laying
siege to a fortification and of destroying it has the
popular name of
siegecraft or 'siege
warfare' and the formal name of
poliorcetics. In some texts this latter term
also applies to the art of building a fortification.
Fortification is usually divided into two branches, namely
permanent fortification and
field
fortification. Permanent fortifications are erected at
leisure, with all the resources that a state can supply of
constructive and
mechanical
skill, and are built of enduring materials. Field fortifications
are extemporized by troops in the field, perhaps assisted by such
local labor and tools as may be procurable and with materials that
do not require much preparation, such as
earth,
brushwood and light
timber, or sandbags (see
sangar).
There is also an intermediate branch known as
semipermanent
fortification. This is employed when in the course of a
campaign it becomes desirable to protect some locality with the
best imitation of permanent defences that can be made in a short
time, ample resources and skilled civilian labor being
available.
Castles are fortifications which are regarded
as being distinct from the generic
fort or
fortress in that it describes a residence
of a monarch or noble and commands a specific defensive
territory.
History
Ancient
From very early history to modern times,
walls have been a necessity for many cities.
Uruk
in ancient
Sumer (Mesopotamia)
is one of the world's oldest known walled cities.
Before
that, the city (or rather proto-city) of
Jericho
in what is now the West Bank
had a wall
surrounding it as early as the 8th millennium BC. The
Ancient Egyptians also built fortresses on the frontiers of the
Nile Valley to protect against invaders from its neighboring
territories. Many of the fortifications of the ancient world were
built with mud brick, leaving many no more than mounds of dirt for
today's archaeologists.
The
Assyrians deployed large
labour forces to build new palaces, temples and defensive
walls.
Some settlements in the
Indus
Valley Civilization were also fortified.
By about 3500 B.C.,
hundreds of small farming villages dotted the Indus
floodplain. Many of these settlements had fortifications and
planned streets.
The stone and mud brick houses of Kot Diji
were
clustered behind massive stone flood dykes and defensive walls, for
neighboring communities quarreled constantly about the control of
prime agricultural land. Mundigak (c.
2500 B.C.) in present
day south-east Afghanistan
has defensive walls and square bastions of sun
dried bricks.
Babylon
was one of
the most famous cities of the ancient world, especially as a result
of the building program of Nebuchadnezzar, who expanded the walls and
built the Ishtar
Gate
.
The Aurelian Walls
Exceptions
were few — notably, ancient Sparta
and ancient
Rome
did not have walls for a long time, choosing to
rely on their militaries for defense instead. Initially,
these fortifications were simple constructions of wood and earth,
which were later replaced by mixed constructions of stones piled on
top of each other without
mortar.
In Central Europe, the
Celts built large
fortified settlements known as
oppida, whose
walls seem partially influenced by those built in the
Mediterranean. The fortifications were continuously expanded and
improved.
In
ancient Greece, large stone walls had
been built in Mycenaean Greece,
such as the ancient site of Mycenae
(famous for
the huge stone blocks of its 'cyclopean'
walls). In classical era Greece, the city of Athens
built a long
set of parallel stone walls called the Long
Walls that reached their guarded seaport at Piraeus
.
Large tempered earth (ie.
rammed earth)
walls were built in
ancient China
since the
Shang Dynasty (c. 1600-1050
BC), as the capital at ancient Ao had enormous walls built in this
fashion (see
siege for more info). Although
stone walls were built in China during the
Warring States (481-221 BC), mass conversion
to stone architecture did not begin in earnest until the
Tang Dynasty (618-907 AD).
In terms
of China's longest and most impressive fortification, the Great Wall had been built since the Qin Dynasty (221-207 BC), although its present
form was mostly an engineering feat and remodeling of the Ming Dynasty
(1368-1644 AD). The large walls of
Pingyao
serve as one example. Likewise, the famous
walls of the Forbidden
City
in Beijing were established
in the early 15th century by the Yongle
Emperor.
The
Romans fortified their cities with
massive, mortar-bound stone walls.
The most famous of these are the largely
extant Aurelian
Walls
of Rome and the
Theodosian Walls of Constantinople
, together with partial remains elsewhere.
These are
mostly city gates, like the Porta Nigra
in Trier
or Newport Arch
in Lincoln
.
Hadrian's
Wall
was built by the Roman
Empire across the width of what is now northern England following a visit by
Roman Emperor Hadrian (AD 76–138) in
AD 122.
Medieval
Roman fort and
hill
forts were the main antecedents of
castles in
Europe, which
emerged in the 9th century in the
Carolingian Empire.
The
Early Middle Ages saw the
creation of some towns built around castles. These cities were only
rarely protected by simple stone walls and more usually by a
combination of both walls and
ditches. From
the 12th century AD hundreds of settlements of all sizes were
founded all across Europe, which very often obtained the right of
fortification soon afterwards.
The founding of urban centers was an important means of territorial
expansion and many cities, especially in eastern Europe, were
founded precisely for this purpose during the period of
Eastern Colonisation. These cities are easy to
recognise due to their regular layout and large market spaces. The
fortifications of these settlements were continuously improved to
reflect the current level of military development.
During the Renaissance era, the Venetians raised great walls around
cities threatened by the Ottoman empire.
The finest examples
are, among others, in Nicosia
(Cyprus) and Chania
(Crete), and
they still stand, to this day.
Early Modern
Medieval-style fortifications were largely made obsolete by the
arrival of
cannons on the 14th century
battlefield. Fortifications in the age of
blackpowder evolved into much lower structures
with greater use of
ditches and
earth rampart that would absorb
and disperse the energy of cannon fire. Walls exposed to direct
cannon fire were very vulnerable, so were sunk into ditches fronted
by earth slopes.
This placed a heavy emphasis on the geometry of the fortification
to allow defensive cannonry interlocking fields of fire to cover
all approaches to the lower and thus more vulnerable walls.
Fortifications also extended in depth, with protected batteries for
defensive cannonry, to allow them to engage attacking cannon to
keep them at a distance and prevent them bearing directly on the
vulnerable walls.
The
result was star shaped fortifications with
tier upon tier of hornworks and bastions, of
which Bourtange
illustrated to the right is an excellent
example. There are also extensive fortifications from
this era in the Nordic states and in
Britain
, the fortifications of Berwick-upon-Tweed
and the harbour archipelago of Suomenlinna
at Helsinki being fine examples.
19th Century
The arrival of
explosive shells in
the nineteenth century led to yet another stage in the evolution of
fortification. Star forts of the cannon era did not fare well
against the effects of high explosive and the intricate
arrangements of bastions, flanking batteries and the carefully
constructed lines of fire for the defending cannon could be rapidly
disrupted by explosive shells.
Worse, the large open ditches surrounding forts of this type were
an integral part of the defensive scheme, as was the covered way at
the edge of the counter scarp. The ditch was extremely vulnerable
to bombardment with explosive shells.
In response, military engineers evolved the
polygonal style of fortification. The ditch
became deep and vertically sided, cut directly into the native rock
or soil, laid out as a series of straight lines creating the
central fortified area that gives this style of fortification its
name.
Wide enough to be an impassable barrier for attacking troops, but
narrow enough to be a difficult target for enemy shellfire, the
ditch was swept by fire from defensive blockhouses set in the ditch
as well as firing positions cut into the outer face of the ditch
itself.
The profile of the fort became very low indeed, surrounded outside
the ditch by a gently sloping open area so as to eliminate possible
cover for enemy forces, while the fort itself provided a minimal
target for enemy fire. The entrypoint became a sunken gatehouse in
the inner face of the ditch, reached by a curving ramp that gave
access to the gate via a rolling bridge that could be withdrawn
into the gatehouse.
Much of the fort moved underground, with deep passages and
tunnels to connect the
blockhouses and firing points in the ditch to the
fort proper, with
magazines and
machine rooms deep under the surface.
The guns however, were often mounted in open emplacements and
protected only by a
parapet - both in order
to keep a lower profile and also because experience with guns in
closed
casemates had seen them put out of
action by rubble as their own casemates were collapsed around
them.
20th Century
Steel-and-
concrete
fortifications were common during the 19th and early 20th
centuries, however the advances in modern warfare since
World War I have made large-scale fortifications
obsolete in most situations. Only underground
bunkers are still able to provide some protection in
modern wars. Many historical fortifications were demolished during
the modern age, but a considerable number survive as popular
tourist destinations and prominent local
landmarks today.
The downfall of permanent fortifications had two causes:
- The ever escalating power of artillery and air power meant that
almost any target that could be located could be destroyed, if
sufficient force was massed against it. As such, the more resources
a defender devoted to reinforcing a fortification, the more combat
power that fortification justified being devoted to destroying it,
if the fortification's destruction was demanded by an attacker's
strategy.
- The second weakness of permanent fortification was its very
permanency. Because of this it was often easier to go around a
fortification, and with the rise of mobile warfare in the beginning
of World War II this became a viable
offensive choice. When a defensive line was too extensive to be
entirely bypassed, massive offensive might could be massed against
one part of the line allowing a breakthrough, after which the rest
of the line could be bypassed. Such was the fate of the many
defensive lines built before and during World War II, such as the Maginot Line, the Siegfried Line, the Stalin Line and the Atlantic Wall. (In the case of the Atlantic
Wall, the purpose of the fortification was to delay an invasion to
allow reinforcement.)
Instead field fortification rose to dominate defensive action.
Unlike the
trench warfare which
dominated
World War I these defenses
were more temporary in nature. This was an advantage because since
it was less extensive it formed a less obvious target for enemy
force to be directed against.
If sufficient power was massed against one point to penetrate it,
the forces based there could be withdrawn and the line could be
re-established relatively quickly. Instead of a supposedly
impenetrable defensive line, such fortifications emphasized
defense in depth, so that as
defenders were forced to pull back or were over-run, the lines of
defenders behind them could take over the defense.
Because the mobile offensives practiced by both sides usually
focused on avoiding the strongest points of a defensive line, these
defenses were usually relatively thin and spread along the length
of a line. The defense was usually not equally strong throughout
however.
The strength of the defensive line in an area varied according to
how rapidly an attacking force could progress in the terrain that
was being defended - both the terrain the defensive line was built
on and the ground behind it that an attacker might hope to break
out into. This was both for reasons of the strategic value of the
ground, and its defensive value.
This was possible because while offensive tactics were focused on
mobility, so were defensive tactics. The dug in defenses consisted
primarily of infantry and antitank guns. Defending tanks and tank
destroyers would be concentrated in mobile "fire brigades" behind
the defensive line. If a major offensive was launched against a
point in the line, mobile reinforcements would be sent to reinforce
that part of the line that was in danger of failing.
Thus the defensive line could be relatively thin because the bulk
of the fighting power of the defenders was not concentrated in the
line itself but rather in the mobile reserves.
A notable exception
to this rule was seen in the defensive lines at the Battle of
Kursk
during World War II,
where German
forces
deliberately attacked into the strongest part of the Soviet
defenses
seeking to crush them utterly.
The terrain that was being defended was of primary importance
because open terrain that tanks could move over quickly made
possible rapid advances into the defenders' rear areas that were
very dangerous to the defenders. Thus such terrain had to be
defended at all cost.
In addition, since in theory the defensive line only had to hold
out long enough for mobile reserves to reinforce it, terrain that
did not permit rapid advance could be held more weakly because the
enemy's advance into it would be slower, giving the defenders more
time to reinforce that point in the line.
For example the
battle of
the Hurtgen Forest
in Germany during the closing stages of World War II is an excellent example of how
impassable terrain could be used to the defenders'
advantage.
Forts
Forts in modern usage often refer to space set aside by governments
for a permanent military facility; these often do not have any
actual fortifications, and can have specializations (military
barracks, administration, medical facilities, or intelligence).
In the
United
States
usage, forts specifically refer to Army fortifications; Marine
Corps fortifications are referred to as camp.
However there are some modern fortifications that are referred to
as forts. These are typically small semi permanent fortifications.
In urban combat they are built by upgrading existing structures
such as houses or public buildings. In field warfare they are often
log, sandbag or gabion type construction.
Such forts are typically only used in low level conflict, e.g.,
counterinsurgency conflicts or very low level conventional
conflicts, e.g., the
Indonesia–Malaysia
confrontation saw the use of log forts for use by forward
platoons and companies. The reason for this is that static above
ground forts can not survive modern direct or indirect fire weapons
larger than mortars, RPGs and small arms.
American West
Forts in the
American Old West
during the
Indian Wars were lightly
fortified enclosures with log or
adobe walls.
They were sometimes only fortified
trading
posts or a combination of a trading post and an Army post.
Famous
forts included Fort
Laramie
and Fort
Bridger
on the Overland Trail
and Bent's
Fort
on the Arkansas River.
See also
View of Alamghiri Gate of Lahore Fort.
Fort components
Types of forts and fortification
Historical Fortresses
Fortification and siege warfare
Famous experts
External links
Les forts Séré de Rivières France 1870 - 1914
http://www.fortiffsere.fr/
References
- Banister Fletcher's A History of Architecture By Banister
Fletcher, Sir, Dan Cruickshank, Dan Cruickhank, Sir Banister
Fletcher. Published 1996 Architectural Press. Architecture. 1696
pages. ISBN 0750622679. pg no 20
- The Encyclopedia of World History: ancient, medieval, and
modern, chronologically arranged By Peter N. Stearns, William
Leonard Langer. Compiled by William L Langer. Published 2001
Houghton Mifflin Books. History / General History. ISBN 0395652375.
pg 17
- Banister Fletcher's A History of Architecture By Banister
Fletcher, Sir, Dan Cruickshank, Dan Cruickhank, Sir Banister
Fletcher. Published 1996 Architectural Press. Architecture. 1696
pages. ISBN 0750622679. pg no 100
- Albania's Chemical Cache Raises Fears About
Others — Washington Post, Monday 10 January
2005, Page A01.
Top topics
Wikis
Quiz
Facts
Map
Search