[1] The first edition was published in four volumes between 1967 and 2002, containing 7.3 million words of text in 3,949 pages, documenting 106,000 headwords.
[2] The second edition is based not only on the Dictionary's own collection of citation slips, but also on a wide range of electronic resources such as the Welsh Prose 1300-1425 website (Cardiff University), JISC Historic Books including EEBO and EECO (The British Library), Welsh Newspapers Online and Welsh Journals Online (National Library of Wales), and the National Terminology Portal (Bangor University).
[2] After three years of work, on 26 June 2014, GPC Online was launched by then First Minister of Wales, Carwyn Jones, AM, in the Welsh Assembly.
[3] On 12 May 2015, it was announced that the Welsh Government had awarded the Centre for Advanced Welsh & Celtic Studies with a grant of £40,500 from the Welsh-language Technology and Digital Media Fund to aid development of a version of the Dictionary for mobile devices.
[4] A year later, on 24 February 2016, free mobile and tablet applications for the Dictionary were announced and launched.