Montagu, having tasted the sweets of office, even so minor a place as that of a Lord of the Treasury, was not content to enjoy such pleasures as a private life could afford. He desired to be somebody. Probably he worried the Government of the day, possibly he pointed out to the leaders of the Whig Party that he was possessed of parts that should not, in justice to his country, be ignored. He may even have approached the Throne. It is not inconceivable that he made himself a nuisance to all concerned.
Anyhow, it was ultimately decided that something must be done with him. But what? Austria and Turkey were at war in 1716; what better than to send Montagu as Ambassador to the Porte, with a mission to endeavour to reconcile the protagonists? He was appointed to this post on June 5.
It was while accompanying her husband on this mission that Lady Mary wrote her famous "Letters during the Embassy to Constantinople," which constitute a very important document on the state of Europe at the time. It is by no means certain, however, that, in the first instance, these reflections were all cast in letter-form; it is much more likely that some were written in a diary. The letters appear as addressed to the Countess of Bristol, to the Princess of Wales, to Mrs. Thistlethwayte, to Lady Rich, to Alexander Pope, to the Abbé Conti, to Miss Sarah Chiswell, to Mrs. Hewet, to Lady Mary's sister, the Countess of Mar, and others.
At the beginning of August, 1716, Montagu, with his wife and son, and, it is to be presumed, his suite, left England, and, after a very bad crossing, landed at Rotterdam. From that city, the cleanliness of which surprised and delighted Lady Mary--"you may see the Dutch maids washing the pavement of the street with more application than ours do our bed-chambers"--the party proceeded by way of the Hague, Nimeguen, Cologne, Frankfort-on-the-Main, Wurzberg, and Ratisbon to Vienna, where they arrived during the first week in September.
Lady Mary was all impatient to go to Court, for, as she put it, "I am not without a great impatience to see a beauty that has been the admiration of so many nations," but she was forced to stay for a gown, without which there was no waiting on the Empress. Presently the gown was ready, and Lady Mary was presented.