I've got it now - I knew there was a Siam connection!
Here's a quote from the Maria Pavlovna bio on the main site
"The birth of a son, in May 1909, failed to make bearable either the marriage or the goldfish bowl of the etiquette-driven Swedish court in which it existed; and in autumn 1911, the canny King Gustav suggested that his son and daughter-in-law take a cruise to Siam, to represent Sweden at the coronation of King Vajiravudh in Bangkok'something of what in modern parlance is called a second honeymoon, and eerily prescient of the similarly unsuccessful trip to the same part of the world undertaken by Prince Charles of Wales and his wife, Diana, some eighty years later.
Siam opened Marie's eyes in several ways. At the same time she was exposed to cultures and traditions, as splendid in their way as anything in Russia, she also discovered something less positive: that it was not possible that she and Vilhelm could go on living together. The intimacy she had hoped to experience with her husband during this change of scene proved a pipe dream; Vilhelm, Marie remembered in later years, seemed to take no impressions from their exotic surroundings, and was sunk in a depression the entire time'evidence that Marie was not doing all the suffering in the relationship."
