The National Library already has a successful website

It also features modern Welsh painters including Sir Kyffin Williams, Will Roberts and Evan Walters.

The site is being unveiled at a ceremony at the National Assembly for Wales in Cardiff Bay.

The second specialised site, 'Campaign!' charts the political and social history of Wales during the 20th Century.

The site is aimed at students from 14 upwards, and anyone with an interest in Welsh political history.

We know there are many people out there who want moreinformation about Wales

Andrew Green

Viewers will be able to hear extracts of Saunders Lewis' revolutionary Fate of the Language speech in 1961, and read the syndicalist Miners' Next Step manifesto as well as being able to access posters, leaflets and photographs.

"We know there are many people out there who want more information about our collections and also about Wales," said Librarian, Andrew Green.

Unknown artist

"The Framed Works of Art and Campaign! projects bring information gathering to their finger tips."

Among the most striking images in the art site is the portrait by an unknown artist of the early 19th Century preacher Christmas Evans.

Also of particular interest is Turner's painting of Dolbadarn Castle in Snowdonia.

The painting took months to execute between 1799 and 1800 and was a major milestone in his development as an artist.

Digitising the images and putting them online enables researchers to delve further into the subject

Paul Joyner

Paul Joyner from the National Library said there had been continuing interest in indigenous Welsh art since the early 1990's and also an interest in Wales's influence on established artists such as Turner and Wilson.

"Digitising the images and putting them online enables researchers to delve further into the subject," Mr Joyner said.

It also provided an answer to the increasing number of requests which the National Library receives from publishers and designers to access images of Wales.

The sites will be unveiled by Tom Middlehurst , Assembly Secretary for Post 16 Education and Culture, later on Wednesday.