Meibion Glyndŵr (Welsh pronunciation: [ˈməibjɔn ɡlɨnˈduːr], also known by its translation Sons of Glyndŵr) was a protest group linked to arson of English-owned holiday homes in Wales.^[1] They were formed in response to the housing crisis in Wales precipitated by large numbers of houses being bought by wealthy English people for use as holiday homes, pushing up house prices beyond the means of many locals.^[1] They were responsible for setting fire to English-owned propierties in Wales from 1979 to the mid-1990s, and only confirm an arrest.^[1][2][3]

The group first came to prominence in 1979 after the Welsh devolution referendum.^[1][4] In the first wave of attacks, eight English-owned holiday homes were destroyed within the space of a month.^[1][2] In 1980, Welsh police carried out a series of raids in Operation Tân ("fire") in an effort to find the culprits.^[1] As part of the operation, Welsh nationalist and publisher Robat Gruffudd and his wife, Enid, were arrested and interrogated.^[2][1] The police were not able to find any evidence of the Gruffudds' involvement in the arson and released them; they were also compensated for their time.^[4][1] Within the next ten years around 220 properties were damaged by the campaign.^[5] It peaked in the late 1980s with the targeting of Conservative MPs' homes with letter bombs, most notably David Hunt, the then Welsh secretary, who was targeted in 1990.^[1]

Four separate movements claimed responsibility for the bombings: Mudiad Amddiffyn Cymru ("movement to defend Wales"), Cadwyr Cymru ("keepers of Wales"), Meibion Glyndŵr, and the Welsh Army for the Workers Republic (WAWR), whose attacks were on political targets in the early 1980s.^{[citation needed]} Meibion Glyndŵr was the only group to have any claim to long-term success, although since the mid-1990s the group has been inactive, and Welsh nationalist violence has ceased, at least on an organisational level.^{[citation needed]} Letters claiming responsibility for attacks were signed "Rhys Gethin", in homage to one of Owain Glyndŵr's most prominent followers.^[6]

A reinvestigation into postal bombings led to the conviction of Sion Aubrey Roberts in 1993.^[1][5] Roberts was sentenced to 12 years but was released after serving 8 years.^[1] He has maintained his innocence while expressing sympathy for Meibion Glyndŵr's cause.^[1] A Plaid Cymru member of parliament, Elfyn Llwyd, speculated that the group was an MI5 front.^[5]

• 1979–94: Meibion Glyndŵr fire-bomb around 220 English-owned homes.^[2][7]
• 18 July 1980: Welsh militants firebombed the home of Welsh Secretary of State Nicholas Edwards, in his rest house in Abergavenny, Monmouthshire.^[7][8] In the same day, a Conservative Party in Cardiff was firebombed by the group.^[9]
• 26 October 1981: An improvised device in an army recruiting office was defused in Pontypridd, prior to a visit by the Prince of Wales.^[10][11] Two days later other bomb was defused by authorities.^[12]
• 28 June 1987: Welsh extremist left two improvised devices in Abergele and Porthmadog^[13][14]
• 1988–89: Meibion Glyndŵr declared that "every white settler is a target". The group also placed incendiary bombs in Conservative Party offices in London and estate agents' offices in London,^[15] Liverpool, Sutton Coldfield, Haverfordwest, Carmarthen and Llandeilo.^[16][17][18]
• 18 March 1989; A series of arson attacks took place in Sutton Coldfield, Haverfordwest, Liverpool and London.^{[19][20][21][22]}
• 22 October 1989; A new ring of arson attacks this time focusing on London.^[23][24][25]
• 1990: Poet and Anglican priest R. S. Thomas calls for a campaign to deface English-owned homes.^{[citation needed]}
• 20–21 June 1990: Four letter bombs, two send to the Secretary of State for Wales and the Member of Parliament for Pembroke at the House of Commons (one of the letters had been slightly wound a woman), one to the Secretary of State for Wales David Hunt, and the last to Nicholas Bennett, both defused.^[26][27]
• 1993: Sion Aubrey Roberts, a member of Meibion Glyndŵr, was jailed for twelve years for sending letter bombs to Conservative politicians.^[1][5]

• Mae rhywun yn gwybod (Somebody Knows) by Alwyn Gruffydd (Gwasg Carreg Gwalch, 2004).
• To Dream of Freedom by Roy Clews, 3rd edition, (Y Lolfa, 2004). Concentrates on MAC and the Free Wales Army in the 1960s. Includes interviews by participants.
• 'Freedom Fighters: Wales's Forgotten War 1963–1993, John Humphries (University of Wales Press, 2008). Looks at FWA, MAC and Meibion Glyndwr with many interviews and historical facts.
• Wyn Thomas, 'John Jenkins: The Reluctant Revolutionary?' (Y Lolfa, 2019). Hardback: ISBN 978-1-912631-07-0; Paperback: ISBN 978-1-912631-14-8
• Wyn Thomas, 'Hands Off Wales: Nationhood and Militancy' (Gomer, 2013). ISBN 978-1-84851-669-4
• Wyn Thomas, 'Hands Off Wales: Nationhood and Militancy' (Y Lolfa, 2022). ISBN 978-1-80099-229-0
• Thomas, Wyn (2022). Hands Off Wales: Nationhood and Militancy. Y Lolfa. ISBN 978-1-80099-229-0.
• Wyn Thomas, 'Tryweryn: A New Dawn?' (Y Lolfa, 2023). ISBN 978-1-91263-148-3
• King, Richard (22 February 2022). Brittle with Relics: A History of Wales, 1962–97 ('Oral history at its revelatory best' DAVID KYNASTON). Faber & Faber. ISBN 9780571295661 – via Google Books.
• Davis, William Virgil (25 July 1901). Miraculous Simplicity: Essays on R.s. Thomas (c). University of Arkansas Press. ISBN 9781610752664 – via Google Books.
• Thomas, Wyn (21 January 2020). John Jenkins: The Reluctant Revolutionary. Y Lolfa. ISBN 9781784618186 – via Google Books.
• Hill, Sarah (5 July 2017). 'Blerwytirhwng?' The Place of Welsh Pop Music. Routledge. ISBN 9781351573467 – via Google Books.
• Ledger, Robert (4 March 2021). Power and Political Economy from Thatcher to Blair: The Great Enemy of Democracy?. Routledge. ISBN 9781000352320 – via Google Books.
• Brooke, Nick (17 April 2018). Terrorism and Nationalism in the United Kingdom: The Absence of Noise. Springer. ISBN 9783319765419 – via Google Books.
• Henken, Elissa R. (25 July 1996). National Redeemer: Owain Glyndŵr in Welsh Tradition. Cornell University Press. ISBN 0801483492 – via Google Books.
• Berger, Matthias D. (18 July 2023). National Medievalism in the Twenty-First Century: Switzerland and Britain. Boydell & Brewer. ISBN 9781843846574 – via Google Books.

• Welsh independence
• Welsh nationalism
• Anti-English sentiment

• "Meibion Glyndwr". BBC - Cymru Ar Yr Awyr.
• "Holiday homes arson anniversary". 12 December 2009 – via news.bbc.co.uk.
• "Arson campaign, 30 years on". 11 December 2009 – via news.bbc.co.uk.
• "Meibion Glyndwr: Home Office papers released about holiday home attacks". 16 March 2017 – via bbc.com.
• Heath, Tony (1 March 2019). "Shadow of Ulster in the Welsh valleys – archive, 1989" – via The Guardian.
• "Second homes: Meibion Glyndwr firebomber admits 1980s attacks". 20 July 2023 – via www.bbc.com.
• Jones, Branwen (12 December 2021). "The story of Meibion Glyndwr and the rise of the nationalist movement". WalesOnline.
• "New book explores what would have happened if Meibion Glyndŵr had been caught". Nation.Cymru. 12 May 2022.
• Hudspith, Jaymelouise; Jones, Branwen (19 December 2021). "Meibion Glyndŵr and a housing crisis that sparked a 20-year arson campaign". North Wales Live.
• "Police 'should close case' on Meibion Glyndwr arsons". 3 January 2017 – via www.bbc.co.uk.
• "Devolution means that the ghost of Meibion Glyndŵr can stay buried". Nation.Cymru. 3 June 2022.
• "BBC Cymru Wales re-examines a highly controversial period in Welsh history in new documentary Firebombers". www.bbc.co.uk.
• Crump, Eryl (19 September 2015). "Crime Files Re-opened: How M15 caught Meibion Glyndwr bombers". North Wales Live.
• Heath, Tony (1 March 2019). "Shadow of Ulster in the Welsh valleys – archive, 1989" – via The Guardian.
• "Wales' decade of arson attacks" – via www.bbc.com.
• "Welsh firebomb conviction is first in 12 years: One man was convicted". The Independent. 10 March 1993.
• Carter, Helen (11 March 2004). "Police take fresh look at Sons of Glyndwr" – via The Guardian.