[citation needed] In 1116 the Welsh of Deheubarth retook the Gower Peninsula and forced Michael to flee his castle which was put to the torch.

In 1220 the Welsh were expelled from the peninsula and the government of Henry III of England returned the barony of Gower to John de Braose who rebuilt both Swansea and Oystermouth castles.

It was portrayed in art in the 18th century as a picturesque ruin, and was restored by George Grant Francis in the 1840s while the castle was owned by the then Duke of Beaufort.

The scheme includes new visitor facilities, an educational space, improvements to access and a 30-foot high glass viewing platform and bridge that leads to Alina's Chapel.

Exposure to the elements has taken its toll on the painting over time but expert Cadw analysis suggests it's a double-arched canopy that contains the figures of angels.

Some of the clear elements of the painting that remain include a wing with multiple feathers and circular shapes that form a head with yellow hair surrounded by a nimbus.

It's thought the painting is both highly important and testimony to the original design of the chapel attributed to Alina de Breos in the early 14th century that once formed part of a larger work of art.