Anna Throndsen has been connected with a set of correspondence called the Casket Letters. These letters which were found in the belongings of a servant of Bothwell, after his flight from Scotland. These letters were used by Mary's half-brother Regent Moray to demonstrate her involvement in the murder of her husband, Lord Darnley. The letters include sonnets and poetry. Some of this material is supposed to have been written by Anna, an idea first suggested by the novelist Robert Gore Browne in his 1937 study of Bothwell. Most British historians contest this, alleging that someone of Nordic nobility would not have had sufficient knowledge of French to draft such prose and there is no reason to connect Throndsen with the Scottish court of Mary or her enemies. Handwriting analysis has also led to dismissal of this speculation.Armstrong-Davison, Meredith Henry (1965) The Casket Letters, University Press of Washington,D.C. Handwriting analysis may not take into consideration the international background of the family, which regularly moved throughout Europe during her childhood, and being nobility would have spoken fluent French, or that the letters exist mostly as copies.
