Conwy Castle fell into disrepair again by the early 17th century.
Charles I sold it to Edward Conway in 1627 for £100, and Edward's son, also called Edward, inherited the ruin in 1631.
In 1642 the English Civil War broke out between the Charles' royalist supporters and Parliament.
John Williams, the Archbishop of York, took charge of the castle on behalf of the king, and set about repairing and garrisoning it at his own expense.
In 1645, Sir John Owen was appointed governor of the castle instead, however, leading to a bitter dispute between the two men.
The Archbishop defected to Parliament, the town of Conwy fell in August 1646 and in November General Thomas Mytton finally took the castle itself after a substantial siege.
The Trevor family petitioned Mytton for the return of property in the castle that they had lent to the Archbishop.

In the aftermath of the siege, Colonel John Carter was appointed governor of the castle and fresh repairs were carried out.
In 1655 the Council of State appointed by Parliament ordered the castle to be slighted, or put beyond military use: the Bakehouse tower was probably deliberately partially pulled down at this time as part of the slighting.
With the restoration of Charles II in 1660, Conway was returned to Edward Conway, the Earl of Conway, but five years later Edward decided to strip the remaining iron and lead from the castle and sell it off.
The work was completed under the supervision of Edward Conway's overseer William Milward, despite opposition from the leading citizens of Conwy, and turned the castle into a total ruin.

By the end of the 18th century, the ruins were considered picturesque and sublime, attracting visitors and artists, and paintings of the castle were made by Thomas Girtin, Moses Griffith, Julius Caesar Ibbetson, Paul Sandby and J. M. W. Turner.
Several bridges were built across the River Conwy linking the town and Llandudno during the 19th century, including a road bridge in 1826 and a rail bridge in 1848.
These improved communication links with the castle and further increased tourist numbers.
In 1865 Conwy Castle passed from the Holland family, who had leased it from the descendants of the Conways to the civic leadership of Conwy town.
Restoration work on the ruins then began, including the reconstruction of the damaged Bakehouse tower.
In 1953 the castle was leased to the Ministry of Works and Arnold Taylor undertook a wide range of repairs and extensive research into the castle's history.
An additional road bridge was built to the castle in 1958.
Already protected as a scheduled monument, in 1986 it was also declared part of the World Heritage Site of the "Castles and Town Walls of King Edward in Gwynedd".

In the 21st century the castle is managed by Cadw as a tourist attraction and 186,897 tourists visited the castle in 2010; a new visitor centre was opened in 2012.
The castle requires ongoing maintenance and repairs cost £30,000 over the 2002–03 financial year.

Conwy Castle was twinned with Himeji Castle, Hyogo prefecture, Japan at a formal ceremony in Himeji on 29 October 2019.
Conwy Castle fell into disrepair again by the early 17th century. Charles I sold it to Edward Conway in 1627 for £100, and Edward's son, also called Edward, inherited the ruin in 1631. In 1642 the English Civil War broke out between the Charles' royalist supporters and Parliament. John Williams, the Archbishop of York, took charge of the castle on behalf of the king, and set about repairing and garrisoning it at his own expense. In 1645, Sir John Owen was appointed governor of the castle instead, however, leading to a bitter dispute between the two men. The Archbishop defected to Parliament, the town of Conwy fell in August 1646 and in November General Thomas Mytton finally took the castle itself after a substantial siege. The Trevor family petitioned Mytton for the return of property in the castle that they had lent to the Archbishop. 
In the aftermath of the siege, Colonel John Carter was appointed governor of the castle and fresh repairs were carried out. In 1655 the Council of State appointed by Parliament ordered the castle to be slighted, or put beyond military use: the Bakehouse tower was probably deliberately partially pulled down at this time as part of the slighting. With the restoration of Charles II in 1660, Conway was returned to Edward Conway, the Earl of Conway, but five years later Edward decided to strip the remaining iron and lead from the castle and sell it off. The work was completed under the supervision of Edward Conway's overseer William Milward, despite opposition from the leading citizens of Conwy, and turned the castle into a total ruin.
By the end of the 18th century, the ruins were considered picturesque and sublime, attracting visitors and artists, and paintings of the castle were made by Thomas Girtin, Moses Griffith, Julius Caesar Ibbetson, Paul Sandby and J. M. W. Turner. Several bridges were built across the River Conwy linking the town and Llandudno during the 19th century, including a road bridge in 1826 and a rail bridge in 1848. These improved communication links with the castle and further increased tourist numbers. In 1865 Conwy Castle passed from the Holland family, who had leased it from the descendants of the Conways to the civic leadership of Conwy town. Restoration work on the ruins then began, including the reconstruction of the damaged Bakehouse tower. In 1953 the castle was leased to the Ministry of Works and Arnold Taylor undertook a wide range of repairs and extensive research into the castle's history. An additional road bridge was built to the castle in 1958. Already protected as a scheduled monument, in 1986 it was also declared part of the World Heritage Site of the "Castles and Town Walls of King Edward in Gwynedd".
In the 21st century the castle is managed by Cadw as a tourist attraction and 186,897 tourists visited the castle in 2010; a new visitor centre was opened in 2012. The castle requires ongoing maintenance and repairs cost £30,000 over the 2002–03 financial year.
Conwy Castle was twinned with Himeji Castle, Hyogo prefecture, Japan at a formal ceremony in Himeji on 29 October 2019.
Conwy Castle