Роман Мстиславич
In the 11th century, Poland and Rus' entered a border dispute and the lands of Lesser Poland and Rus' (called "Ruthenia" in Latin) were changing hands constantly. In the early Middle Ages, the area of what later would become Galicia was scarcely populated, as the region was settled by Rus' peoples from the east and by Poles from the west. Border-clashes took place in the lands of Przemyśl, Sanok, Drohiczyn and Vladimir-in-Volhynia. The decline of Kievan Rus' gave Poland the opportunity to seize control of the regions. In 1199, an armed campaign led by Leszek the White helped to install Roman the Great on the throne in Vladimir-in-Volhynia. In 1205, however, Roman declared war on Poland. The Polish chronicler, Jan Długosz, tried to give reasons for Roman's declaration of war: