Duke Duchess End Portugal Visit on 640th Treaty Anniversary

The Duke and Duchess of Edinburgh have concluded a three-day official visit to Portugal, marking the 640th anniversary of the Treaty of Windsor, the world's oldest diplomatic alliance still in force. The tour, which began in Lisbon and ended in Porto, celebrated the enduring historic ties between the United Kingdom and Portugal.

The royal couple's engagements commenced at the Portuguese National Archive in Lisbon, where they inaugurated a special exhibition. For the first time since 1386, the original English and Portuguese copies of the Treaty of Windsor were displayed together, alongside ten wax seals. While viewing the centuries-old documents, Prince Edward remarked that the Portuguese looked after their documents better than the British. Sophie noted the remarkably fine script of the treaty.

A year after the treaty was signed, the alliance was further cemented by the marriage of Portugal's King João I to England's Philippa of Lancaster. Their children, known as the "Illustrious Generation," were instrumental in Portugal's age of maritime exploration.

During their day in the capital, the Duke and Duchess also took a ride on one of Lisbon's iconic historic yellow trams,...