Kate Middleton, Queen Letizia and Queen Maxima to reunite at the Order of the Garter ceremony

The event will take place on 17 June

by Andrea Caamano

The Duchess of Cambridge will be joined by two of the most glamourous royals at this year's Order of the Garter ceremony, which will take place in Windsor Castle on 17 June.

HELLO! understands that Queen Letizia of Spain and Queen Maxima of the Netherlands are flying in to support their husbands, King Felipe VI and King Willem-Alexander, as the Queen formally invests them with the Order's insignia in the Throne Room of the Castle.

Letizia and Maxima will no doubt be in good hands, as Kate is due to attend alongside the Duchess of Cornwall and the Countess of Wessex. The mother-of-three has attended nearly every Garter ceremony since 2011, only missing it in 2015 and 2018 as she was on maternity leave. Her husband Prince William is a member of the Order.

The Duke and Duchess of Cambridge pictured during 2016's ceremony

Both Felipe and Willem-Alexander have received the special award from Her Majesty in the past two years. King Felipe VI, like his father and grandfather, became what is known as a 'Stranger Knight' or 'Extra Knight Companion' of the prestigious Order of the Garter back in July 2017, during the Spanish state visit.

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King Willem-Alexander was appointed a supernumerary Knight of the Garter in October last year, on the first day of his and Maxima's state visit.

King Felipe with the Queen in 2017

Although knights are usually formally invested the year after they are appointed, Felipe VI was forced to skip 2018's Order of the Garter ceremony due to a diary clash. At the time, he was in America, on an official visit to Texas ahead of meeting with Donald Trump in Washington, meaning that he and Willem-Alexander will coincide during 2019's ceremony.

Membership in the Order is limited and includes the Queen, who is sovereign of the Garter, several senior members of the royal family such as Prince Charles and Prince William, and twenty-four knights chosen in recognition of their work.

King Willem-Alexander with the Queen in 2018

MORE: Queen Elizabeth leads the British royal family at the 2018 Order of the Garter ceremony in Windsor

Knights of the Garter are chosen personally by the sovereign to honour those who have held public office, who have contributed in a particular way to national life or who have served the sovereign personally. These have included Marshal of the RAF, Lord Stirrup, and former Prime Ministers Sir John Major and Sir Winston Churchill.