The wills of thousands of people dating back to the 14th century including the Welsh Robin Hood will be posted on the web by the end of the year.
The wills will be scanned in as digital documents
The National Library of Wales, based at Aberystwyth will put more than 200,000 wills of Welsh people stretching back more than 700 years onto the internet.
Among those available will be Welsh bandit of the road Twm Sion Cati and Welsh Methodist revivalist leaders, William Williams, Pantycelyn and Howell Harris.
A UK-wide scheme by the National Archive to put up millions of wills, including those of Williams Shakespeare, Jane Austen and Horatio Nelson is already up and running.
Internet users can search and download digital images of original documents for a small fee, including Napoleon Bonaparte's will.
The National Library of Wales has yet to decide on the details of how it will run its own scheme, according to Sion Jobbins of the National Library of Wales.
"We need to discuss if people have to pay for downloaded wills but we expect to use the same sort of system as the National Archive," he said.
Twm Sion Cati, was an outlaw-hero from Tregaron who lived between 1530 and 1620.
In his youth he made his living as a highwayman and trickster and was famed for his kindness to his victims.
In later life he became a magistrate and became a member of the ruling classes.
"Once it is up and running the wills placed on-line will be of enormous interest to the public and be available at the National Library's own website," said Mr Jobbins.