Tomas Čelkis. The development of the concept of the Grand Duchy of Lithuania western borders in 13th – 16th centuries
In old languages demarcation terms were polysemous and used to express concepts of a border as an object and a sign. Territorial sections used to become limits for pre-statehood disputes however demarcation of the said sections was no longer a spontaneous phenomenon. In 1358 the Grand Duchy of Lithuania concluded its first international demarcation treaty with Masuria, in which the demarcation was still close to old tribal concepts. The campaign of identification of Western borders with the Teutonic Order during the Vytautas times was a new phase of development, which evidenced emergence of manifestations of the concept of a borderline.After the borders identification campaign, in the 15th century the borders renewal process was going on, during which the borders of the Vytautas times were already, called the old ones and true ones, which is evidenced by the importance of changes, which occurred during the Vytautas times when a new territorial self-perception was emerging. In 1473 a new border treaty was concluded with Livonia.In the 1st half of the 16th century the border renewal procedure, determined by the necessity to manage the internal colonization process, which reached the borderline territories of the Grand Duchy and its adjacent states, was further developed. In most cases private domains were legitimated as a state border, the stability of which was a concern of all the stakeholding social groups. Demarcation of borders was improved in the 16th century. In the acts the demarcation lines were accurately registered and described. In 1545 the following demarcation line was built, i. e. the pillar with the states’ coats of arms and names. Such demarcation shows that in the 1st half of the 16th century the line character of the state border was in its final phase of development, which meant the emergence of the concept of the state’s territory in the Western part of the Grand Duchy of Lithuania.