Troyden, Duke of Redania, was the brother of the King Radovid I the Great and later, Earl of Kovir. He founded the House of Trojden. As a young man, he was considered to be extremely well connected, if somewhat of a slippery character. He was jealous and openly displayed his hatred for his brother, so he was given the title of Count of Kovir basically to get him out of Redania, and ideally as far away as possible. Officially, Trojden was a vassal ruler, but he was not obliged to pay tribute, his only obligation was to do "no harm".
Traidenis (Polish: Trojden) was the Grand Duke of Lithuania in years 1269/70-1282.