Kristoffer Throndsen (c. 1500–1565), posthumously also with the family name Rustung, was a squire, admiral, feudal overlord in Norway and Denmark, privateer captain and pirate.

Kristoffer served Archbishop Olav Engelbrektsson, the interregnum leader of Norway, in the last years of the Kalmar Union.

Kristoffer appealed for pardon from Christian III, probably for the murder but also for his piracy of the Norwegian coast under foreign flags, under which he attacked Danish ships and installations in Norway after 1536/1537.

Anna is famous in modern-day Norway, for her days in the court of Mary Queen of Scots, during her marriage to James Hepburn, Lord Bothwell.

The closest to contemporary sources primarily consist of two 17th century ancestry charts which says his parents were Trond Sigurdsson Rustung of Seim and Karen Koll of Nessa.

Vincens Lunge, the feudal overlord of Bergenhus at the time then formed a fleet, and also received aid from the archbishop who sent Kristoffer with a few ships.

Lunge was however soon startled by rumours of the Danish king deposing the feudal lord of Akershus, and wanted Kristoffer to stay for his defence for a while.

[6] The relationship between Vincens Lunge and the Catholic archbishop gradually worsened during the 1530s, resulting in numerous conflicts between them, as well as Inger, Lady of Austraat.

[6] The next years, Kristoffer operated as a privateer, with a letter of marque titled "Christoph von Trundheim, Marskalk in Norweger" from Frederick II, Count Palatine of the Rhine.

[6] Around 1542-43 he got pardoned by Christian III of Denmark after he had applied for it, and was engaged as a naval officer, which Denmark-Norway had a desperate need for.

His missions included sailing to Iceland to calm down a small rebellion, and later fighting with his fleet in the Northern Seven Years' War against the Swedish-Norwegian admiral Jakob Bagge.

[note 5] He is known to have written his signature "Christoffer Trundsß", suggesting that he himself was the origin of the family name "Tronds" which many of his daughters is known to have used.