A visit to the Walker Art Gallery, Liverpool, in 1892, where he spent some hours in front of Frederick Leighton's Perseus and Andromeda, revealed a new world to him.

In 1911, Williams received a commission from King George V to work on a commemorative painting of the Investiture of Edward, Prince of Wales at Caernarfon Castle.

As well as attending the ceremony, he visited Buckingham Palace, where the Royal Family sat for him in order to complete the detail of the picture.

During the First World War, he painted The Welsh at Mametz Wood, now in Amgueddfa Cymru – National Museum Wales.

Shortly before his death in 1934, he presented to the Salvation Army a large picture of the Thames Embankment scene at night which he called Why?

In 1973, an exhibition was organised on the centenary of William's birth at the National Museum of Wales, Glynn Vivian Art Gallery and Maesteg Town Hall.