Image copyright Oriel Plas Glyn y Weddw Image caption Ogmore Castle by John Cyrlas Williams

A new exhibition is aiming to showcase a long-forgotten Welsh artist after 100 previously-unknown paintings were found in the attic of his family home.

During the 1920s John Cyrlas Williams was touted as the "real thing" by his patron, the Liberal politician Winifred Coombe-Tennant.

But by the age of 30, his painting career had been cut short by a mixture of alcoholism and bipolar disorder.

The paintings, found in a house in Porthcawl, will go on show in Gwynedd.

Image copyright Oriel Plas Glyn y Weddw Image caption Self portrait by John Cyrlas Williams

The exhibition at Oriel Plas Glyn y Weddw in Llanbedrog, Pwllheli, is aiming to restore Williams's reputation as an artist.

After he stopped painting, he spent the remainder of his life as a civil service clerk, and by the time of his death at the age of 63 in 1965, his artwork had slipped into obscurity - until now.

Art historian Peter Lord, who is curating the exhibition, said that, but for a keen-eyed auctioneer who rescued the paintings from going on a bonfire, the collection would have been lost forever.

Image copyright Oriel Plas Glyn y Weddw Image caption Dark boats, Martigues, by John Cyrlas Williams

"I first learnt about Williams while researching my biography of famous patron of the arts Winifred Coombe-Tennant, who appears to have bought most of his known work," he said.

"Then one day I got a call from my friend, artist Mike Jones, who told me, 'You know that bloke you were on about? Well I think you'd better get yourself down to Clydach, because I think there's a load of his paintings in an auction room down here'.

"They were pretty grubby and almost unrecognisable before we had them restored."

Image copyright Oriel Plas Glyn y Weddw Image caption The Head Dress by John Cyrlas Williams

Williams was born into a wealthy Welsh-American mine-owning family.

In 1918, he went to train at the Newlyn School in Cornwall under Stanhope Forbes, before moving to France, where he worked at the Colarossi atelier in Paris, at Pont Aven in Brittany and at Martigues in the south, following in the footsteps of Augustus John.

He reached the zenith of his powers during the mid 1920s, heady times for Welsh art, with his contemporaries including Evan Walters, Archie Griffiths and Cedric Morris.

Image copyright Oriel Plas Glyn y Weddw Image caption Market Day, Concarneau, by John Cyrlas Williams

Image copyright Oriel Plas Glyn y Weddw Image caption Carriage horses by John Cyrlas Williams

According to Mr Lord, Williams's background meant his work differed markedly from that of his peers.

"Williams worked so much in France, he brings a very different approach compared to Archie Griffiths and Evan Walters, who were very concerned with the mining industry and the depression of the 1920s and 30s," he added.

The exhibition, entitled A Brief Flowering, will be on show at Oriel Plas Glyn y Weddw from 20 March until 15 May 2016.