Throughout the winter of 1940-1941 the German Luftwaffe maintained a ferocious nightly bombing campaign against London and the major towns and cities of Britain. On 2 January 1941 it was the turn of Cardiff to suffer its heaviest raid of the war – 165 people were killed and 427 were seriously injured.

Early in the raid parachute – borne land-mines fell on Llandaff. The parachute of the first mine was said to have become entangled with the tip of the Cathedral Spire and fell in the South Churchyard  and exploded, creating a vast crater and destroying many graves, also severely damaging the Chapter House and the roof of the Nave and Chancel.

Much of the roof collapsed inwards, destroying most of the furnishings including the Font, Pulpit, Choir and Canon Stalls and the Organ. The Rossetti Triptych and some of the Victorian stained glass had already been taken out and safely stored but the remainder was all lost. There was no outbreak of fire. Immediately after the raid the debris was cleared away and the damaged structure was made safe. The top section of the spire was taken down and the remnants of the roof were demolished.

On the following Sunday worship was held in the Deanery but this soon moved into the Prebendal House. Meanwhile, work started on the re-ordering of the Lady Chapel and the Sanctuary and the repair of their roofs to create as much seating space as possible but this was not completed until April 1942. This space then served as the Cathedral until 1957.

No further repair or restoration was possible until after the war had ended in 1945.

Although the war had ended in 1945 materials and labour remained restricted to essential building for many years and little progress on the restoration had been made when the Cathedral Architect, Sir Charles Nicholson died suddenly. The recently installed Dean Glyn Simon appointed George Pace as his replacement. Pace was a young architect who was establishing a practice in York, specialising in ecclesiastical architecture.

On the advice of Sir Charles, the Dean and Chapter had earlier instructed him to put the cathedral back as it had been but Pace and Dean Simon adopted a different view. Pace chose to restore earlier work wherever possible but where new work was necessary it was to be frankly of the 20^th century but carefully integrated with the existing and this philosophy characterised the whole of the restoration. When Glyn Simon was elected Bishop of Swansea and Brecon he was succeeded as Dean by Eryl Thomas who worked equally closely with George Pace and continued the same philosophy.

In addition to repairing that which had survived the restoration introduced many new features including the coffered timber ceiling to the nave and Chancel, the re-ordering of the Sanctuary, the Majestas Arch supporting a section of the organ and the Christ in Majesty sculpture by Sir Jacob Epstein and the new memorial Chapel for the Welsh Regiment, incorporating the Processional Way leading to the Prebendal House. The Rossetti painting was not returned to the High Altar but was incorporated in a new St Illtyd Chapel at the west end of the North Aisle. The lost stained glass was not replaced but instead Pace used natural lighting to great effect throughout.

The restoration was crowned when a great Service of Thanksgiving was attended by the Queen and the Duke of Edinburgh in August 1960, almost 20 years after the bombing and it was to be one of the finest works of the long and distinguished career of George Pace.