[Much of the information originally here was in 2005 used to create the Wikipedia article on TJ, which has since been updated & amplified by multiple editors. I've therefore abbreviated the information here, to avoid unnecessary duplication.]
TJ was described as "one of the six most important men in Europe", and also (by a certain MP) as "the King of Wales"(!). He was an advisor to 4 Prime Ministers (Lloyd George, Bonar Law, Baldwin and MacDonald), and his diary threw much light on politics "behind the scenes". 311 volumes of his papers at the National Library of Wales "comprise one of the finest archives in the country" (many of his other papers are here at Aberystwyth University and here in the National Archives).
He was also unrivalled at extracting money from rich people for worthwhile causes, notably adult education. He was Chairman of Gregynog Press (Gwasg Gregynog) and effectively set up the Arts Council, as well as the Army Bureau of Current Affairs (to supply 'mental stimulant' to British troops: when officers stationed at Street Acre during WW2 asked him what to do with the hundreds of books in the house, he sent a two-word reply: "Read them!").
Towards the end of his life he became President of UCW Aberystwyth, was awarded the Gold Medal of the Honourable Society of Cymmrodorion (the highest honour a Welshman can receive from his country), and finally agreed (under protest, having refused other national honours) to become a Companion of Honour. The biography by Ted Ellis, published by the University of Wales Press, is highly recommended; for a shorter summary of his life see one of many obituaries.
Many of TJ's own books may still be found e.g. via Amazon:
To mark the 50th anniversary of his death, a commemoration was held on 5 October 2005 at 7:30 p.m. at the Capel Moreia, Moriah Street, Rhymney, NP22 5LD. The event focused on:
Other speakers included Professor Peter Stead (Cardiff University) and Professor John Elliott (Chairman of the Honourable Society of Cymmrodorion). The event was supported by the Gwent Association of Voluntary Organisations, and most of the evening was captured on (amateur) video.
An earlier celebration in Rhymney, 1939
TJ (centre front) and the Coleg Harlech Council
TJ and George Bernard Shaw
This page produced by Ben Jones as part of the family records.