John, the fourth Marquess, acquired the castle in 1900 on the death of his father, and the family estates and investments around the castle began to rapidly reduce in size.
Cardiff had grown hugely in the previous century, its population increasing from 1,870 in 1800 to around 250,000 in 1900, but the coal trade began to diminish after 1918 and industry suffered during the depression of the 1920s.
John only inherited a part of the Butes' Glamorgan estates, and in the first decades of the 20th century he sold off much of the remaining assets around Cardiff, including the coal mines, docks and railway companies, with the bulk of the land interests being finally sold off or nationalised in 1938.

Development work on the castle continued.
There was extensive restoration of the medieval masonry in 1921, with architect John Grant rebuilding the South Gate and the barbican tower, and reconstructing the medieval West Gate and town wall alongside the castle, with the Swiss Bridge being moved in 1927 to make room for the new West Gate development.
Further archaeological investigations were carried out into the Roman walls in 1922 and 1923, leading to Grant redesigning the northern Roman gatehouse.
The second half of the castle stables were finally completed.
The Animal Wall was moved in the 1920s to the west side of the castle to enclose a pre-Raphaelite themed garden.
The grand staircase in the main range was torn out in the 1930s.
During World War II, extensive tunnels within the medieval walls were used as air-raid shelters, with eight different sections, able to hold up to 1,800 people in total, and the castle was also used to tether barrage balloons above the city.

In 1947, the John, the fifth Marquess, inherited the castle on the death of his father and faced considerable death duties.
He sold the very last of the Bute lands in Cardiff and gave the castle and the surrounding park to the city on behalf of the people of Cardiff; the family flag was taken down from the castle as part of the official hand-over ceremony.
The castle was protected as a grade I listed building and as a scheduled monument.

Cardiff Castle is now run as a tourist attraction, and is one of the most popular sites in the city.
The castle is not fully furnished, as the furniture and fittings in the castle were removed by the Marquess in 1947 and subsequently disposed of; an extensive restoration has been carried out, however, of the fittings originally designed for the Clock Tower by Burges.
The Royal Welsh College of Music and Drama, founded in 1949, was housed in the castle's main range for many years, but moved into the castle's former stables north of the castle in 1998.
A new interpretation centre, which opened in 2008, was built alongside the South Gate at a cost of £6 million, and the castle also contains "Firing Line", the joint regimental museum of the 1st The Queen's Dragoon Guards and the Royal Welsh.

The castle has been used for a range of cultural and social events.
The castle has seen various musical performances, including by Tom Jones, Green Day and the Stereophonics, with a capacity to accommodate over 10,000 people.
During the 1960s and 1970s the castle was the setting for a sequence of military tattoos.
John, the fourth Marquess, acquired the castle in 1900 on the death of his father, and the family estates and investments around the castle began to rapidly reduce in size. Cardiff had grown hugely in the previous century, its population increasing from 1,870 in 1800 to around 250,000 in 1900, but the coal trade began to diminish after 1918 and industry suffered during the depression of the 1920s. John only inherited a part of the Butes' Glamorgan estates, and in the first decades of the 20th century he sold off much of the remaining assets around Cardiff, including the coal mines, docks and railway companies, with the bulk of the land interests being finally sold off or nationalised in 1938.
Development work on the castle continued. There was extensive restoration of the medieval masonry in 1921, with architect John Grant rebuilding the South Gate and the barbican tower, and reconstructing the medieval West Gate and town wall alongside the castle, with the Swiss Bridge being moved in 1927 to make room for the new West Gate development. Further archaeological investigations were carried out into the Roman walls in 1922 and 1923, leading to Grant redesigning the northern Roman gatehouse. The second half of the castle stables were finally completed. The Animal Wall was moved in the 1920s to the west side of the castle to enclose a pre-Raphaelite themed garden. The grand staircase in the main range was torn out in the 1930s. During World War II, extensive tunnels within the medieval walls were used as air-raid shelters, with eight different sections, able to hold up to 1,800 people in total, and the castle was also used to tether barrage balloons above the city.
In 1947, the John, the fifth Marquess, inherited the castle on the death of his father and faced considerable death duties. He sold the very last of the Bute lands in Cardiff and gave the castle and the surrounding park to the city on behalf of the people of Cardiff; the family flag was taken down from the castle as part of the official hand-over ceremony. The castle was protected as a grade I listed building and as a scheduled monument.
Cardiff Castle is now run as a tourist attraction, and is one of the most popular sites in the city. The castle is not fully furnished, as the furniture and fittings in the castle were removed by the Marquess in 1947 and subsequently disposed of; an extensive restoration has been carried out, however, of the fittings originally designed for the Clock Tower by Burges. The Royal Welsh College of Music and Drama, founded in 1949, was housed in the castle's main range for many years, but moved into the castle's former stables north of the castle in 1998. A new interpretation centre, which opened in 2008, was built alongside the South Gate at a cost of £6 million, and the castle also contains "Firing Line", the joint regimental museum of the 1st The Queen's Dragoon Guards and the Royal Welsh.
The castle has been used for a range of cultural and social events. The castle has seen various musical performances, including by Tom Jones, Green Day and the Stereophonics, with a capacity to accommodate over 10,000 people. During the 1960s and 1970s the castle was the setting for a sequence of military tattoos.
Cardiff Castle