When Princess Alice, the Countess of Athlone and youngest granddaughter of Queen Victoria, first set foot in Saudi Arabia on a February morning in 1938, it was a historic occasion.
The princess, then 55, was not only the first British royal to visit the country, but also the first from Europe, and the trip paved the way for closer Anglo-Saudi ties for decades to come. The fact that it was a female royal who made this first venture into Saudi Arabia made the tour all the more extraordinary.
It was an important time for relations between the two countries, with the recent consolidation of the kingdom and just after the discovery of oil there. But far from being a planned diplomatic move, the visit had sprung from a chance meeting at Ascot racecourse two years earlier. George V had taken ill and Princess Alice ended up sitting next to the young Prince Saud, the eldest son of the Saudi King Abdulaziz.
"Out of politeness I said how sorry I was that I had never visited Arabia," the princess later wrote in her memoirs. "He at once asked: 'Why not come to Arabia?' I murmured something to the effect that no ladies had ever been there, but he said if I did not mind sleeping in tents, it was easy. I replied that I had often slept in camps without tents at all and accepted right away."
Two years later HMS Enterprise docked in Jeddah harbour and the epic three-week journey across the kingdom began. The princess, accompanied by her husband, the Earl of Athlone, travelled from Jeddah on the west coast south into the hills above Mecca, and east across the mountains to the desert capital of Riyadh. They met tribal chieftains, camped and hunted in the desert, and donned traditional Saudi dress.
Princess Alice was the first member of the British royal family to meet King Abdulaziz, and the only one to be invited for a meal with the monarch.
She later recalled: "He himself was a huge man, a great gentleman with a most engaging manner. He was charming and full of jokes, and we became his hero-worshippers. I thanked him very much for inviting me as he had never before asked a female to an audience or a meal."
A collection of 322 remarkable photographs charting the journey, many taken by Princess Alice herself, are now in possession of the King Abdulaziz Public Library in Riyadh. A selection went on display this month at the Royal Geographical Society in London.
The images, along with Princess Alice's written records of her visit, paint a vivid picture of the young Kingdom of Saudi Arabia in the years before the oil boom brought rapid development.
Princess Alice died on January 3, 1981, at the age of 97.
Journey of a Lifetime, an exhibition of photographs of Princess Alice's visit to Saudi Arabia, is at the Royal Geographical Society in London until August 26.