In 1814 Lord Bute's grandson, John, inherited his title and the castle.
In 1825 the new Marquess began a sequence of investments in the Cardiff Docks, an expensive programme of work that would enable Cardiff to become a major coal exporting port.
Although the Docks were not particularly profitable, they transformed the value of the Butes' mining and land interests, making the family immensely wealthy.
By 1900, the family estate owned 22,000 acres (8,900 ha) of land in Glamorgan.

The second Marquess preferred to live on the Isle of Bute in Scotland and only used Cardiff Castle occasionally.
The castle saw little investment and only four full-time servants were maintained on the premises, meaning that cooked food had to be brought across from the kitchens at a nearby hotel.
The castle remained at the centre of the Butes' political power base in Cardiff, however, with their faction sometimes termed as "the Castle party".
During the violent protests of the Merthyr Rising of 1831, the Marquess based himself at Cardiff Castle, from where he directed operations and kept Whitehall informed of the unfolding events.
The governance of the then town of Cardiff was finally reformed by an Act of Parliament in 1835, introducing a town council and a mayor, severing the link with the castle constable.

John, 3rd Marquess of Bute, inherited the title and castle in 1848.
He was then less than a year old, and as he grew up he came to despise the existing castle, believing that it represented a mediocre, half-hearted example of the Gothic style.
The young Lord Bute engaged the architect William Burges to undertake the remodelling of the castle.
The two shared a passion in medieval Gothic Revivalism and this, combined with Bute's huge financial resources, enabled Burges to rebuild the property on a grand scale.
Burges brought with him almost of all of the team that had supported him on earlier projects, including John Starling Chapple, William Frame and Horatio Lonsdale.
Burges's contribution, in particular his research into the history of the castle and his architectural imagination, was critical to the transformation.

Work began on Lord Bute's coming of age in 1868 with the construction of the 150-foot (46 m) high Clock Tower.
The tower, built in Burges's signature Forest of Dean ashlar stone, formed a suite of bachelor's rooms, comprising a bedroom, a servant's room and the Summer and Winter smoking rooms.
Externally, the tower was a re-working of a design Burges had previously used in an unsuccessful competition entry for the Royal Courts of Justice in London.
Internally, the rooms were sumptuously decorated with gildings, carvings and cartoons, many allegorical in style, depicting the seasons, myths and fables.
In his A History Of The Gothic Revival, written as the tower was being built, Charles Locke Eastlake wrote of Burges's "peculiar talents (and) luxuriant fancy."
The Summer Smoking Room rested at the top of the structure and was  two storeys high with an internal balcony that, through an unbroken band of windows, gave views of the Cardiff Docks, the Bristol Channel, and the Glamorgan countryside.
The floor had a map of the world in mosaic.
The sculpture was created by Thomas Nicholls.

As the rest of the castle was developed, work progressed along the rest of the 18th century range including the construction of the Guest Tower, the Arab Room, the Chaucer Room, the Nursery, the Library, the Banqueting Hall and bedrooms for both Lord and Lady Bute.
In plan, the new castle followed the arrangement of a standard Victorian country house quite closely.
The Bute Tower included Lord Bute's bedroom and ended in another highlight, the Roof Garden, featuring a sculpture of the Madonna and child by Ceccardo Fucigna.
 Bute's bedroom contained extensive religious iconography and an en-suite bathroom.
The Octagon Tower followed, including an oratory, built on the spot where Bute's father died, and the Chaucer Room, the roof of which is considered by historian Mark Girouard to be a "superb example of Burges's genius".

The central part of the castle
In 1814 Lord Bute's grandson, John, inherited his title and the castle. In 1825 the new Marquess began a sequence of investments in the Cardiff Docks, an expensive programme of work that would enable Cardiff to become a major coal exporting port. Although the Docks were not particularly profitable, they transformed the value of the Butes' mining and land interests, making the family immensely wealthy. By 1900, the family estate owned 22,000 acres (8,900 ha) of land in Glamorgan.
The second Marquess preferred to live on the Isle of Bute in Scotland and only used Cardiff Castle occasionally. The castle saw little investment and only four full-time servants were maintained on the premises, meaning that cooked food had to be brought across from the kitchens at a nearby hotel. The castle remained at the centre of the Butes' political power base in Cardiff, however, with their faction sometimes termed as "the Castle party". During the violent protests of the Merthyr Rising of 1831, the Marquess based himself at Cardiff Castle, from where he directed operations and kept Whitehall informed of the unfolding events. The governance of the then town of Cardiff was finally reformed by an Act of Parliament in 1835, introducing a town council and a mayor, severing the link with the castle constable.
John, 3rd Marquess of Bute, inherited the title and castle in 1848. He was then less than a year old, and as he grew up he came to despise the existing castle, believing that it represented a mediocre, half-hearted example of the Gothic style. The young Lord Bute engaged the architect William Burges to undertake the remodelling of the castle. The two shared a passion in medieval Gothic Revivalism and this, combined with Bute's huge financial resources, enabled Burges to rebuild the property on a grand scale. Burges brought with him almost of all of the team that had supported him on earlier projects, including John Starling Chapple, William Frame and Horatio Lonsdale. Burges's contribution, in particular his research into the history of the castle and his architectural imagination, was critical to the transformation.
Work began on Lord Bute's coming of age in 1868 with the construction of the 150-foot (46 m) high Clock Tower. The tower, built in Burges's signature Forest of Dean ashlar stone, formed a suite of bachelor's rooms, comprising a bedroom, a servant's room and the Summer and Winter smoking rooms. Externally, the tower was a re-working of a design Burges had previously used in an unsuccessful competition entry for the Royal Courts of Justice in London. Internally, the rooms were sumptuously decorated with gildings, carvings and cartoons, many allegorical in style, depicting the seasons, myths and fables. In his A History Of The Gothic Revival, written as the tower was being built, Charles Locke Eastlake wrote of Burges's "peculiar talents (and) luxuriant fancy." The Summer Smoking Room rested at the top of the structure and was  two storeys high with an internal balcony that, through an unbroken band of windows, gave views of the Cardiff Docks, the Bristol Channel, and the Glamorgan countryside. The floor had a map of the world in mosaic. The sculpture was created by Thomas Nicholls.
As the rest of the castle was developed, work progressed along the rest of the 18th century range including the construction of the Guest Tower, the Arab Room, the Chaucer Room, the Nursery, the Library, the Banqueting Hall and bedrooms for both Lord and Lady Bute. In plan, the new castle followed the arrangement of a standard Victorian country house quite closely. The Bute Tower included Lord Bute's bedroom and ended in another highlight, the Roof Garden, featuring a sculpture of the Madonna and child by Ceccardo Fucigna.  Bute's bedroom contained extensive religious iconography and an en-suite bathroom. The Octagon Tower followed, including an oratory, built on the spot where Bute's father died, and the Chaucer Room, the roof of which is considered by historian Mark Girouard to be a "superb example of Burges's genius".
The central part of the castle 
Cardiff Castle