One small step for Wales; one giant leap for Westminster.
Two years after it last met, and a year after the House of Commons changed its rules to allow Welsh to be spoken in its debates, the Welsh Grand Committee held its first bilingual debate. You can watch it here.
Shadow Welsh Secretary Christina Rees called it "the first Welsh Welsh Grand". The Welsh Grand, for those who don't know it, consists of the 40 Welsh MPs plus up to five MPs from elsewhere. It has no real power but exists to debate various issues and their impact on Wales.
Today's meeting was ostensibly to debate the chancellor's Autumn Budget. Yes, last year's Budget statement, which Philip Hammond delivered on November 22. The Welsh Grand doesn't do topical.
A lot of the debate focused on what wasn't in the Budget as much as what was. Whenever two or three Welsh MPs are gathered together, the Swansea tidal lagoon crops up in conversation. Two Conservatives - David Jones and Simon Hoare - pressed ministers for a positive decision.
Alun Cairns repeated the government's point that it has to be value-for-money. He didn't say when that decision would be taken although I'm told it will be "sooner rather than later" which is progress from "in due course".
Despite a few technical problems - screeching feedback from the translation sets - everyone agreed the new bilingual forum worked well.
Almost half Wales's 40 MPs speak Welsh. A couple of learners - Labour's Kevin Brennan and Anna McMorrin - chose to deliver all or part of their speeches in the language of heaven.
For a parliament where the only permitted languages are English and Norman French, it was something of a breakthrough.
Plaid Cymru's parliamentary leader, Liz Saville Roberts, hopes the Welsh Grand 'experiment' will lead to wider use of minority languages. With one eye on plans to refurbish the Palace of Westminster, she said: "We are in a brave new technological world. We are certainly talking about the adaptations and the future of this establishment.
"Why shouldn't there be the means to translate from other languages including Welsh so that we can use these languages here in the Westminster Parliament?"