Princes William, Harry cheer on opposing teams at Rugby World Cup

/ Source: TODAY

Prince William, Prince Harry and Duchess Catherine of Cambridge had a sporting Saturday watching old rivals England and Wales face off in the Rugby World Cup — although the royals were split along lines of the rivalry.

Prince Harry, Prince William, Duke of Cambridge and Catherine; Duchess of Cambridge attend the England v Wales match during the Rugby World Cup 2015 on September 26, 2015 at Twickenham Stadium, London, United Kingdom.WireImage

William and Kate both cheered on Wales, with Will wearing the team's red coat and Kate donning a red scarf. The couple also sang the Welsh national anthem at the start of the match.

Meanwhile, Harry routed for England, donning a white shirt in support of his team.

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Prince Harry, Prince William, Duke of Cambridge and Catherine; Duchess of Cambridge attend the England v Wales match during the Rugby World Cup 2015 on September 26, 2015 at Twickenham Stadium, London, United Kingdom. WireImage

Harry is vice patron of the body that runs English rugby, as well as the honorary president of the Rugby World Cup 2015, while William is the vice patron of the Welsh Rugby Union.

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Prince Harry, Prince William, Duke of Cambridge and Catherine; Duchess of Cambridge attend the England v Wales match during the Rugby World Cup 2015 on September 26, 2015 at Twickenham Stadium, London, United Kingdom. WireImage

William and Kate's support of Wales is also related to the fact that the couple spent the first years of their marriage living in the U.K. country, on the north-west Welsh island of Anglesey.

Wales beat England 28-25 at the Twickenham Stadium in London, in what was the most-watched sports event of the year in Britain.

Prince Harry, Prince William, Duke of Cambridge and Catherine; Duchess of Cambridge attend the England v Wales match during the Rugby World Cup 2015 on September 26, 2015 at Twickenham Stadium, London, United Kingdom. WireImage

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Earlier in September, all three royals stepped out for the Rugby World Cup's opening ceremony, and England's game against Fiji.

Prince Harry, Prince William, Duke of Cambridge and Catherine; Duchess of Cambridge attend the England v Wales match during the Rugby World Cup 2015 on September 26, 2015 at Twickenham Stadium, London, United Kingdom. WireImage

The month also marks the return to public duties for Duchess Kate, who began making her first solo royal appearances — to a mental health center for children and a women's prison in London — after giving birth to Princess Charlotte in May.