Cardiff Arms Park & Millennium Stadium

Cardiff RFC and Wales shared a pitch at Cardiff Arms Park until the 1969-70 season, when an agreement between Cardiff Athletic Club and the Welsh Rugby Union moved the club to a purpose-built ground and launched the National Stadium project, opened by 7 April 1984. A committee was set up in 1994 to consider redeveloping it, and in 1995 the WRU was chosen to host the 1999 Rugby World Cup.

The 1962 design had by then been cut by the Taylor Report from 65,000 to 53,000, against Twickenham's 75,000 and Murrayfield's 67,000. Options included a third tier or a 100,000-seat site at Bridgend, whose county borough council leader told The Times that a new national stadium in Cardiff was "half-baked". The Bridgend plan was discounted because of the car parking it needed, and the committee chose to rebuild on the Arms Park site - the fourth redevelopment there - realigned from west-east to north-south and given a sliding roof.

Clearing the site took down the National Stadium, the Wales Empire Pool, BT's Cardiff Empire Telephone Exchange and the Social Security offices in Westgate Street. A team led by Rod Sheard at Lobb Sport Architecture, later merged into Populous, designed the ground; WS Atkins were the structural engineers and Laing the contractor. Mike Otlet of WS Atkins designed the retractable roof.

The £121 million cost came from private investment, £46 million from the Millennium Commission - for whose contribution the stadium was named - debentures sold to supporters, and loans; it left the WRU heavily in debt. The bowl was left open at one end: the WRU could not secure funding for a new North Stand, the Millennium Commission would not allow its money to go towards a ground for Cardiff RFC next door, and talks with the club were unsuccessful. The break is known as Glanmor's Gap, after the then WRU chairman Glanmor Griffiths.

The first major event was a rugby union test on 26 June 1999, when Wales beat South Africa 29-19 before a crowd of 29,000, their first win over the Springboks. Wales was the main host of the 1999 Rugby World Cup, and seven of its 41 matches, including the final, were played at the stadium. It staged pool matches and quarter-finals in 2007 and 2015, and, from 2013, Judgement Day, the double-header of the four Welsh United Rugby Championship sides, whose 2016 edition drew 68,262, the highest in that league's history.

From 2000 to 2009 the Wales football team played most of its home matches here, the first against Finland drawing a then-record Welsh home crowd of over 66,000. The original Wembley had housed the Welsh rugby team while Cardiff was being rebuilt; the favour was returned from 2001, while the new Wembley went up, with the FA Cup, League Cup and play-off finals coming to Cardiff.

Liverpool won the first FA Cup final there in 2001, beating Arsenal 2-1, and the last in 2006, beating West Ham United on penalties after a 3-3 draw. The first eleven major finals were all won by the side occupying the home dressing room; Stoke City ended the run in 2002, beating Brentford 2-0 after Paul Darby carried out a feng shui blessing. In 2012 the stadium was one of six football venues for the London Olympics and held the opening event of the Games, a 1-0 win for Great Britain's women over New Zealand.

A ten-year naming-rights deal with the Principality Building Society was announced on 8 September 2015, opposed by some fans on social media, and on 22 January 2016 the ground was formally renamed the Principality Stadium, the bilingual name lit up at an evening ceremony. The stadium is owned by Millennium Stadium plc, a subsidiary of the WRU, and is the home of the Wales rugby union team, which plays all home fixtures there.

Its record crowd, just over 78,000, came on 28 October 2017, when Anthony Joshua kept his heavyweight titles with a tenth-round stoppage of Carlos Takam. In February 2019 disabled capacity was raised from 168 to 214, cutting the overall figure from 74,500 to 73,931. On 28 March 2020 it was announced that the stadium would become a temporary £8 million field hospital for COVID-19 patients; by the weekend of 11-12 April it had 330 beds.

UEFA rules on the names of non-tournament sponsors meant the 2017 Champions League final was staged under the name National Stadium of Wales, Real Madrid beating Juventus 4-1 on 3 June 2017. The same will apply to the six Euro 2028 fixtures announced for the stadium in November 2025, among them the opening match, a round-of-16 tie and a quarter-final.