Title: Tower of London
Content:  The Tower of London, officially Her Majesty's Royal Palace and Fortress of the Tower of London, is a historic  castle on the north bank of the River Thames in central London. It lies within the London Borough of Tower Hamlets, which is separated from the eastern edge of the square mile of the City of London by the open space known as Tower Hill. It was founded towards the end of 1066 as part of the Norman Conquest. The White Tower, which gives the entire castle its name, was built by William the Conqueror in 1078 and was a resented symbol of oppression, inflicted upon London by 
Title: Tower of London
Content:  Victorious at the Battle of Hastings on 14 October 1066, the invading Duke of Normandy, William the Conqueror, spent the rest of the year securing his holdings by fortifying key positions. He founded several castles along the way, but took a circuitous route toward London; only when he reached Canterbury did he turn towards England's largest city. As the fortified bridge into London was held by Saxon troops, he decided instead to ravage Southwark before continuing his journey around southern England. A series of Norman victories along the route cut the city's supply lines and in December 1066, isolated and intimidated, its leaders yielded London without 
Title: White Tower (Tower of London)
Content:  The castle which later became known as the Tower of London was begun by William the Conqueror in 1066, and was built as a timber fortification enclosed by a palisade. In the next decade work began on the White Tower, the great stone keep that still dominates the castle today. The precise date of the White Tower's foundation is unknown, and it is also uncertain how long the construction took. It is traditionally held that construction began in 1078. This is because the Textus Roffensis records that Gundulf, Bishop of Rochester, oversaw the building work under instruction from William the Conqueror. Dendrochronological evidence 
Title: Timeline of London
Content:  of the city including St Paul's Cathedral. ; 1091 – 23 October: London tornado of 1091 destroys the wooden London Bridge and severely damages the church of St Mary-le-Bow and other buildings. ; 1099 – Westminster Hall built. ; 1100 ; 5 August: Coronation of Henry I at Westminster Abbey by Maurice (bishop of London). ; 15 August: Ranulf Flambard, Bishop of Durham, becomes the first person imprisoned in the Tower of London, by the new king for supposed embezzlement; on 3 February 1101 he becomes the first person to escape from the Tower. ; 1106 – Southwark Priory refounded by Augustinians. 
Title: Tower of London
Content:  is uncertain. William made Gundulf, Bishop of Rochester, responsible for its construction, although it may not have been completed until after William's death in 1087. The White Tower is the earliest stone keep in England, and was the strongest point of the early castle. It also contained grand accommodation for the king. At the latest, it was probably finished by 1100 when Bishop Ranulf Flambard was imprisoned there. Flambard was loathed by the English for exacting harsh taxes. Although he is the first recorded prisoner held in the Tower, he was also the first person to escape from it, using a smuggled rope secreted in a 
Title: Timeline of London
Content: 1009 – August: Vikings attack London. ; 1014? ; Olaf II Haraldsson of Norway perhaps attacks London and burns the wooden London Bridge in support of Æthelred. ; Claimed origin of Borough Market. ; 1016 – May: Battle of Brentford: King Edmund Ironside defeats Cnut the Great, who then besieges London. ; 1066 ; 25 December: William the Conqueror crowned King of England in Westminster Abbey. ; The Tower of London is chartered. ; c. 1078 – Construction of the White Tower (Tower of London) begins; it is probably largely completed by 1088. ; 1087 – An early fire of London destroys 
Title: Tower of London
Content:  fight. Between 1066 and 1087, William established 36 castles, although references in the Domesday Book indicate that many more were founded by his subordinates. The new ruling elite undertook what has been described as "the most extensive and concentrated programme of castle-building in the whole history of feudal Europe". They were multi-purpose buildings, serving as fortifications (used as a base of operations in enemy territory), centres of administration, and residences. William sent an advance party to prepare the city for his entrance, to celebrate his victory and found a castle; in the words of William's biographer, William of Poitiers, "certain fortifications were completed in the city 
Title: Tower of London
Content:  the restlessness of the huge and brutal populace. For he [William] realised that it was of the first importance to overawe the Londoners". At the time, London was the largest town in England; the foundation of Westminster Abbey and the old Palace of Westminster under Edward the Confessor had marked it as a centre of governance, and with a prosperous port it was important for the Normans to establish control over the settlement. The other two castles in London – Baynard's Castle and Montfichet's Castle – were established at the same time. The fortification that would later become known as the Tower of London was built 
Title: Tower of London
Content:  the south-east corner of the Roman town walls, using them as prefabricated defences, with the River Thames providing additional protection from the south. This earliest phase of the castle would have been enclosed by a ditch and defended by a timber palisade, and probably had accommodation suitable for William. Most of the early Norman castles were built from timber, but by the end of the 11th century a few, including the Tower of London, had been renovated or replaced with stone. Work on the White Tower – which gives the whole castle its name – is usually considered to have begun in 1078, however the exact 
Title: Fortifications of London
Content: The White Tower, the first part of the Tower of London to be built, was constructed in 1078 to the east of the city, between Aldgate and the river Thames; and Baynard's Castle, to the south west next to the River Fleet. ; A third fortification, Montfichet's Castle, was built to the north west by Gilbert de Monfichet, a native of Rouen, and relative of William’s. After the Norman conquest in 1066 the city fortifications were added to, as much to protect the Normans from the people of the City of London as to protect London from outside invaders. King William had two fortifications built: Later in the medieval period the walls were redeveloped with the addition of crenellations, more gates and further bastions.

Question: who built the tower of london in 1066?
Answer: William the Conqueror.