Prince William is Prince Harry's best man after being asked by brother ahead of Royal wedding to Meghan Markle

Prince Harry has asked his brother the Duke of Cambridge to be his best man at his wedding to Meghan Markle.

Kensington Palace said William was "honoured" to be asked and was looking forward to supporting his brother at St George's Chapel, Windsor for the May 19 Royal wedding.

Prince Harry served as his older brother's best man at his wedding to Kate, the Duchess of Cambridge, in 2011.

An adorable image of a young William and Harry wearing police officers' hats and blue polo shirts was shared on the Kensington Palace official account alongside the announcement.

The Duke of Cambridge, 35, who became a father for the third time on Monday, will have prime position by Harry’s side during the ceremony.

His role will involve performing ceremonial duties on the day, which most likely include holding the couple’s rings.

It is also traditional for the best man to make a speech on the wedding day.

Kensington Palace said in a statement on Thursday: "Prince Harry has asked his brother The Duke of Cambridge to be his Best Man at his wedding to Ms Meghan Markle.

"Prince Harry served as best man to The Duke of Cambridge at his wedding to Miss Catherine Middleton in 2011.

"The Duke of Cambridge is honoured to have been asked, and is very much looking forward to supporting his brother at St George's Chapel, Windsor on May 19th."