From Wales to Downing Street: S4C’s landmark new series maps the Welsh language’s far-reaching influence

S4C’s landmark new series promises an eye‑opening, emotional and at times surprising journey into the story of the Welsh language – with a story that even includes a couple of British Prime Ministers.

Guto Harri will present the second episode of S4C’s new Stori’r Iaith.

Boris Johnson, who was Prime Minister from 2019 – 2022, appears in the programme reflecting on his attempts to learn Welsh and his fascination with the language’s Latin influence.

Johnson says: “Well I love Welsh and I made a huge, a heroic effort to try to master Welsh when I decided to become an MP for a constituency in Clwyd South and I learnt various phrases like Peint o gwrw chwerw os gwelwch yn dda.

“Put it this way, I loved learning it but deploying it I found quite difficult…”

Guto, who was formerly Downing Street Director of Communications, describes the intensity of life working for Boris Johnson, someone he knew for four decades.

He recalls being one of very few Welsh‑speaking voices inside the most powerful rooms in Downing Street: “There aren’t many Welsh speakers who have been around the big table where the most important discussions happen”

“I don’t believe that I have ever worked such long hours… but I enjoyed every second.”

In the programme, Guto reflects on his own connection with the language while uncovering the pivotal role played by Welsh speakers far beyond Wales.

“The Welsh language is absolutely fundamental to who I am,” Guto explains.

Despite spending most of his adult life outside Wales, Guto explains that distance has only strengthened his sense of Welsh identity.

“I am a Welshman living in London and who feels more Welsh than ever,” he says, adding that Welsh speakers in London have played a central part in the language’s story over centuries.

The programme explores the extraordinary influence of Welsh communities in Britain’s capital – from the radical societies of the 18th century to the early publishing industry that helped standardise and spread the language.

Guto traces that history with contributions from leading experts including Dr Marion Löffler and Dr Llewelyn Hopwood.

One of the programme’s major revelations is that some of Wales’s most iconic cultural institutions – including the Eisteddfod and the Gorsedd – owe much of their existence to political radicalism in London and beyond.

Guto describes how Iolo Morganwg and the Cymmrodorion Society were fuelled by the ideals of the French Revolution, using the language of freedom and democracy to reshape Welsh cultural life.

“The societies in London radicalise… they decide to re-establish the Eisteddfod as something national but also radical” explains Rhian Medi Bishop, a historian on the Welsh living in London.

Guto also reflects on his admiration for what he calls “the greatest Welshman” – former Prime Minister David Lloyd George.

He notes how George’s determination to protect the language was shaped by his uncle’s experience of being punished, and left deaf in one ear, for speaking Welsh.

It was this story that later inspired George to support legislation allowing children up to the age of seven to be taught Welsh in schools.

At the core of the episode is Guto’s pride in passing Welsh to the next generation, despite raising his family outside Wales, highlighting his determination to keep the language alive within his family.

He concludes with a reflection on the current momentum behind the language: “Popular culture is on the rise… Welsh is cool or sexy even and there’s excitement… that the Welsh language is alive.”

Guto’s episode of Stori’r Iaith is both personal and historical, charting a story that stretches from medieval manuscripts to modern London, from political revolution to family identity.

It reveals a language shaped not only in Wales but across borders and generations.

A language, as Guto paraphrases from a popular Welsh poem, that he cannot escape from – “ni allaf ddianc rhag hon.”

You can watch Stori’r Iaith: Guto Harri on Wednesday, 11 March at 9pm. It will also be available on demand on S4C Clic and BBC iPlayer.