Anna Tronds (c. 1540–1607), known in English as Anna Throndsen and posthumously as Anna Rustung, was a Dano-Norwegian noblewoman. In English and Scots history, Anna Throndsen is best known for her marriage to James Hepburn, 4th Earl of Bothwell (which later earned her the nickname Skottefruen ("The Scottish Lady"), a man who later married Mary, Queen of Scots. Anna Throndsen is also known for her possible but much debated and disputed involvement in drafting some of the famous Casket Letters; these letters being the principal evidence used in the murder trial of Mary, Queen of Scots.
Anna was the eldest daughter of Kristoffer Throndsen, a famous 16th century Norwegian admiral, nobleman and wartime privateer (pirate). During the final years of independent Norway, 1532–1536, Kristoffer served as admiral of the Norwegian fleet, in the service of his cousin, Olav Engelbrektsson, the last archbishop of Norway. Some years after Norways political subsumption by Denmark, in 1539, Kristoffer was appointed to serve King Frederick II as a Naval commander. He served as an admiral in the Danish fleet, then as Danish Royal Consul in Copenhagen. Kristoffer took his Norwegian family, including Anna, to Copenhagen at this time. As a young woman, Anna assisted her father in consular affairs in the Danish capital.
Anna was married to Bothwell, by handfasting, while he was doing business in Denmark. The marriage was considered legitimate under Dano-Norwegian law, but was, and is still, treated as dubious or invalid, by English and Scots historians. For this reason, most English books refer to her, incorrectly, as a "mistress", or jilted lover. Anna's later Bergen lawsuit against Bothwell (ca. 1570), which held him to account for wrongful behaviour as a husband, as well as writings of the Scots Earl of Moray, lend credence to the fact that a marriage did transpire.
A notorious scoundrel, Bothwell married another woman in France, shortly after marrying her, and soon set his eyes on the Queen, Mary Stuart. While in Scotland, Anna was frustrated and unhappy. She was rumoured to have borne a child, this possibly being William, the only son of Bothwell. In the mid-1560s, she left Scotland to return to her family; her mother and siblings had returned to Norway on her father's death. Shortly thereafter, Bothwell proceeded to marry Mary Stuart, Queen of Scots, after having allegedly murdered her husband, Darnley.