What is a Castle or Chateau's History, and why is it called a castle?
 Wherever the Romans established themselves they fortified their cities by building a
 wall around them for protection from their enemies.  Following the decline of Rome,  about the middle of the forth-century AD, the feudal lords built simple wooden fortified
 living places at the top of a hill or upon an artificial mound called a moat.  Ideally, the
 structures were built were they could command a view of the countryside.  until the
 12^th-century, the fortification’s main building materials remained earth and timber. 

 When fortified places where not strategically placed on an island in a river [Château
 Gaillard, Les Andelys, France], or in another body of water [such as Mont-St-Michel
 in Normandy], they were surrounded by a ditch.  Eventually, the ditches were
 filled with water to become moats.   

 During the Middle Ages [the 5^th-century through the 14^th century], when Europe was
 divided into many small states and conflicts were common, castles played a central
 role in the feudal political and military system.  Under this system, the kings granted
 land to the nobles in return for military and other services to be rendered by the
 nobles.  The kingpin of this system was the castle that helped the king or noble
 defend his lands.  The castle served as home, barracks, armory, storehouse, prison,
 treasury and administrative center. 

 A wooden stockade was erected, around the motte, upon which were built the
 fortification’s structures.  By the late 9^th-century, the wooden wall was being replaced
 by a thick stonewall.  The use of a single stonewall oftentimes gave way to a series
 of raised masonry walls that gradually became thicker and which were topped with
 wide crenellated parapets.  The open areas, within these walls, became known as
 the bailey [courtyard].  By the 11th century, the motte-and-bailey castle [from the
 Latin word castellum, meaning a ‘small fortified place’] configuration had become
 dominant. 

 As siege warfare became more sophisticated, the castle builders built increasingly
 stronger defensive bastions.  The stone castle’s walls could be up to 33 feet (10
 meters) thick.  In most cases, round towers stood at the corners of the walls and
 along the lengths of the walls.  Guards walked along the tops of the walls and
 towers, where they were protected by defensive structures called battlements.  The
 battlements consisted of stone uprights known as merlons and open spaces called
 crenels.  The merlons shielded the guards from enemy missiles.  Through the
 crenels, the guards could shoot arrows or drop rocks on attackers.   

 The motte was usually built up from earth that had been excavated from the building
 of the moat; it was usually topped by a palisade.  An enemy attacking the castle had
 to break through the defenses of one or more baileys before he could reach the
 moat’s defenses. 

 The Normans fashioned the next step in castle development.  This was the addition
 of a towering masonry keep [donjon] within the bailey.  The keep often rose some 40
 to 50 feet 12 – 15 meters] and had small windows set into thick walls.  Concurrently,
 the moats became wider and were traversed by a drawbridge that was raised and
 lowered from within the fortification’s walls. 

 In the 12^th and 13^th-centuries, when the Crusaders were returning from the Holy land,
 they brought memories of the imposing Islamic stone fortifications with them.  These
 helped to transform their castles.  The castle apartments were transferred to more
 robust buildings that were built within additional bailey battlements.  They became
 the castle’s final line of defense.   

 With the advent of canons, in the 15^th-century, the fortified castle [château fort]
 began to give way to the French type chateau ‘country house’ or ‘royal residence’. 
 This transition was in no small part due to Charles VIII’s 1494 invasion of Italy to
 capture the kingdom of Naples.  In his march toward Naples his canon bombarded
 and destroyed numerous castles.  So thorough was the destruction that the kings
 and nobility, of Western Europe, came to see the castle’s Achilles’ heel.  Fortified
 castle building all but ceased.