Conisbrough Castle is a medieval fortification in Conisbrough, South Yorkshire, England. The castle was initially built in the 11th century by William de Warenne, the Earl of Surrey, after the Norman Conquest of England in 1066. Hamelin Plantagenet, the illegitimate, parvenu brother of Henry II, acquired the property by marriage in the late 12th century. Hamelin and his son William, Earl of Surrey rebuilt the castle in stone, including its prominent -high keep. The castle remained in the family line into the 14th century, despite being seized several times by the Crown. The fortification was then given to Edmund of Langley, passing back into royal ownership in 1461.
Conisbrough Castle fell into ruin, its outer wall badly affected by subsidence, and was given to the Carey family in the 16th century. Its derelict state prevented it from involvement in the English Civil War of the 17th century and the remains were bought by the Duke of Leeds in 1737. Sir Walter Scott used the location for his 1819 novel Ivanhoe and by the end of the 19th century the ruins had become a tourist attraction.
The state took over the management of the property in 1950, but by the 1980s the visitor facilities were felt to be unsuitable, leading to a three-way partnership being created between the local council, the state agency English Heritage and a local charitable trust to develop the castle. The keep was re-roofed and re-floored in the 1990s with the help of European Union funding. English Heritage took over control of the castle in 2008 and continues to operate the property as a tourist attraction.
The castle is made up of an inner and an outer bailey, the former surrounded by a stone curtain wall defended by six mural or fortified towers and the castle keep. The inner bailey would have included a hall, solar, chapel and other service buildings of which only the foundations survive. The design of Conisbrough's keep is unique in England, and the historians Oliver Creighton and Stephen Johnson consider it an "architectural gem" and "one of the finest examples of late Norman defensive architecture". The keep comprises a circular central tower with six massive buttresses; its four floors would have included a main chamber and a private chamber for the lord above it. Although militarily weak, the design would have been a powerful symbol of Hamelin Plantagenet's new social status as a major lord.
History
11th – 12th centuries
thumb|upright=1.7|Aerial photograph in 2007, showing the [[outer bailey|outer and inner baileys (bottom left and top right)]]
Conisbrough Castle was founded by William de Warenne, the first Earl of Surrey, who had taken part in the Norman conquest of England in 1066 and was rewarded by his father-in-law, William the Conqueror, with extensive estates in Yorkshire, Norfolk and Sussex. As part of these, Lord de Warenne was given the manor of Conisbrough, which had previously been owned by the late Saxon king Harold II.
William built his castle on a rocky Magnesian Limestone spur surrounded by steep banks, and the fortification included a motte, an inner bailey protected by an earth bank and palisades, an outer bailey, and possibly a timber keep. The castle was located around above the river and would have dominated this part of the Don Valley. It was positioned directly opposite the village, which probably contained the old Anglo-Saxon burh.
The castle was held by William's son, also called William, from 1088 to 1138, and then by his son, another William, until his death in 1147. Conisbrough and the earldom then passed through Isabel, William's daughter, to her first husband, William de Blois, and then on to her second husband, Hamelin Plantagenet, whom she married in 1163. Hamelin was the illegitimate half-brother of King Henry II, who had arranged the marriage, and the union brought him great wealth. Hamelin extensively rebuilt the castle around 1180 to 1190, including constructing the stone keep; given his parvenu status, he probably hoped to reinforce perceptions of his new elevated rank. King John visited the castle in 1201.
13th – 15th centuries
thumb|upright=1.7|The inner bailey seen from the east, showing the former locations of the gatehouse and the solar block (left), and the castle's hall (right)
The castle continued in the ownership of Hamelin Plantagenet's family, passing to his son William de Warenne in 1202. The inner bailey was levelled and William built a hall and service buildings inside the castle, again in stone. Conisbrough was inherited by William's young son John de Warenne in 1239, but he was still a minor and the castle was initially managed by his mother, Maud.
Under John, Conisbrough's constables carried out a range of what the historian Stephen Johnson terms "colourful if rather unlawful dealings"; one was ultimately charged with having conducted "devilish and innumerable oppressions".
The castle passed to John's grandson, also called John, who, in 1304, married Joan de Barr. Edward was overthrown by his wife Isabella in 1326 and the castle was returned to John. Richard of York then inherited the castle, and on his death in 1460 during the Wars of the Roses it passed to his son Edward, who seized the throne in 1461, bringing Conisbrough back into Crown ownership once again.
16th – 19th centuries
thumb|upright=1.6|Engraving of the castle from afar in 1785
By the 16th century Conisbrough Castle was in a poor state of repair, and a royal survey carried out in 1537 and 1538 showed that the gates, bridge and parts of the walls had collapsed in a spectacular land slippage, and that one floor of the keep had also fallen in. The collapse of the walls was a consequence of the instability of the topsoil on top of the limestone spur, which was a mixture of clay and sandstone; once the clay was washed away over time, the remaining sandstone proved extremely unstable and liable to crack.
Henry VIII gave the ruins to the Carey family, who retained it until it passed by marriage into first the Heviningham and then the Coke families. The castle was not involved in the events of the English Civil War in the 17th century, and escaped the slighting that affected many similar properties, probably because the collapse of the outer walls had already made it indefensible and of little military value.
In 1811 the novelist Sir Walter Scott passed by the castle and later used it as the location for his novel Ivanhoe, published in 1819. Scott only had a partial view of the property from the road and the events portrayed in the novel, set at the end of the 12th century, are fictitious; Scott believed the castle to have been Saxon in origin, a view shared by many 19th-century commentators. Although the writer John Wainwright was still able to praise the "picturesque view" around the castle in 1826, the antiquarian Ecroyd Smith commented with concern in 1887 on the changing character of the location, in particular the factories that were growing up around the new railway line and the "murky atmosphere" the industrial works created.
In 1859 Francis D'Arcy-Osborne, the Duke of Leeds, died, leaving Conisbrough to his nephew, Sackville Lane-Fox, the Baron Conyers. If finances allowed it, he also urged the reinstallation of a roof and wooden floors. A reported £500 was spent by the trustees renovating the castle ruins, including the construction of a lodge in the outer bailey for the castle keeper, completed in 1885, and improvements to the footpaths.