Donimir of Troy was a Redanian knight from the castle Baldhorn and a participant in many battles, including both battles at Sodden.
He's described as being thin as a bean pole, and wearing red and black emblazoned with three lions passant.
In 1263, Donimir joined a northern army in Upper Sodden, and fought in the ensuring first battle, against the invading Nilfgaardian Army. After being soundly defeated, he rode north into Lower Sodden and fought in the famous Battle of Sodden Hill.
After the First Northern War, he travelled to Bleobheris for Dandelion's concert under the tree, and got into an argument with Sheldon Skaggs.
Travelling to Toussaint
In 1275, Donimir travelled to the duchy of Toussaint, and joined the knights participating in the large tournament taking place near Beauclair, as a first-year competitor.
Geralt could train on him in swordmanship, if the witcher joined the tournament. Donimir later chose to join a team with the witcher.