Queen's 90th: See which fellow monarch visited Windsor castle for a pre-birthday lunch

The Queen will ring in her milestone 90th birthday with a wealth of engagements on Thursday (Apr. 21) and plenty of additional fetes in the coming months, but first she looked to the camaraderie of a fellow European monarch.

HELLO! Online's sister publication HOLA! reports that the monarch invited Queen Sofía of Spain to a private lunch on Tuesday 19 April.

The pair sat down for the lavish meal at Windsor Castle, the Queen's royal residence in Berkshire, where she has been carrying out engagements in the lead-up to her birthday. As the intimate luncheon took place just two days before, Queen Sofía, 77, no doubt took the opportunity to congratulate Her Majesty and give her warmest wishes in person.

TAP TO VIEW GALLERYQueen Elizabeth and Queen Sofia The Queen invited Queen Sofia of Spain to a private lunch

The royals have managed to maintain a strong friendship over the years, despite the Queen having to address the issue of Gibraltar during her reign.

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Both royals are also distantly related as they descend from Queen Victoria. Queen Sofía's father was King Paul of Greece, the great-grandson of Queen Victoria. Her Majesty, meanwhile, is the great-great-granddaughter of Queen Victoria.

Throwback of Queen Elizabeth and Queen Sofia The two royals are distantly related as they descend from Queen Victoria

The Queen has only carried out one official state visit to Spain, which took place in October 1988. Sofía was pictured warmly welcoming her counterpart with a kiss on both cheeks.

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At the time the Queen acknowledged the peaceful transition from dictatorship to democracy following General Franco's death in 1975. "The democratic Parliament before me, and the manner in which it was achieved, will stand out as one of the brightest pages in your nation's long and proud history," she said in a speech.

Couples shot of Queen Elizabeth and Queen Sofia with their husbands The Spanish royals were welcomed to Windsor Castle in 1986

Two years before in 1986, the Queen and Prince Philip welcomed Sofía and her husband King Juan Carlos to Windsor Castle. A state banquet was held in honour of the Spanish royals.

This was the last state visit from Spain. Current monarchs King Felipe and Queen Letizia were due to carry out their first state visit to the UK in March however the trip had to be postponed amid Spain's political situation.

An official statement issued by the Spanish Foreign Office said: "Notice is given that due to the process of the formation of a new government currently underway in Spain, [the state] visit has been postponed."

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