Welsh MPs hailed a "historic" milestone in the House of Commons, as the country's language was used for the first time in a committee on which they all sit.
The Welsh Grand Committee heard speeches in both English and Welsh as MPs discussed the impact of last year's Budget on Wales.
The committee, whose members include all 40 Welsh MPs and several from elsewhere in the UK, gives members an opportunity to debate issues relevant to Wales, and was meeting for the first time in two years.
Opening the debate, Wales Secretary Alun Cairns stated: "I am proud to be speaking to you all today in the Welsh language - the language that is important to me and the community that I represent and which is integral to the history and culture of Wales."
This "historic day for the parliament and for Wales", as Mr Cairns later called it, was made possible by a resolution of the House of Commons on January 9 this year.
The resolution is part of a wider move to relax rules surrounding the use of the Welsh language in the UK Parliament, following a campaign led by Labour's MP for Clwyd South Susan Elan Jones.
Ms Jones declared: "This momentous milestone required significant persistence on our part to bring this to pass. I am proud to have been so involved and to have received such tremendous support."