Opening of legal proceedings in civil proceedings on Ukrainian lands as part of Poland and Lithuania (middle of the 14th – middle of the 17th centuries)

The article examines the peculiarities of opening proceedings in a lawsuit based on the analysis of medieval Polish-Lithuanian legislation, which maintained its influence in Ukraine for almost half a millennium. The author conducts an analysis of the system of courts that operated at that time, as their status had a significant impact on the particularity of the exercise of the right to sue. It is noted that the feudal legislation was very careful to ensure that the claim was not filed in the wrong court contrary to the established rules of judicial jurisdiction. To a certain extent, this was connected with the presence in some states of the privilege to try in a court where representatives of their state tried (state courts). 
Attention is drawn to preserving the heredity of opening proceedings in the case from the «princely era» at the initial stages of the occupation of the territory of Ukraine by Poland and Lithuania. But in the future, such a procedure for opening proceedings on the basis of a claim is formed, which in some ways resembles a modern civil process. 
The author examines the written form of the claim and analyzes its details, indicating their significance. A comparison of Polish and Lithuanian legislation on this issue is carried out. In particular, the Complete Code of Laws of Casimir the Great of 1347 and the Formula processus of 1523 and the three Statutes of the Grand Duchy of Lithuania of 1529, 1566 and 1588 are compared on the other, respectively. It is noted that at the first stages, the Lithuanian legislation more succinctly defined the details of the claim, but later they were almost the same, which is explained by the rapprochement of Poland and Lithuania and the formation of the single state of the Polish-Lithuanian Commonwealth in 1569. However, both states did not compactly contain thesedetails of the claim in one article , and were scattered not only on different articles, but sometimes also on different chapters of feudal codes. 
The existence of strict rules for preserving the authenticity of the text of the lawsuit is noted, which should guarantee not only the interests of the parties to fair justice, but also the authority of the judiciary, since the lawsuit was issued on behalf of the sovereign, that is, it was a judicial procedural document. It indicates various types of payments and property penalties that could take place at the initial stage of proceedings in a civil case. First of all, they were directed to official earning of money by court employees and prevention of abuse of procedural rights by the parties. 
Compared to the previous period, the role of the state in opening legal proceedings is growing significantly. She, with the help of various officials, helps the plaintiff bring his dispute to an official hearing before the court, so that he can claim what is rightfully his. The stage of opening proceedings in a civil case ends with the registration of a lawsuit in government books (for example, Zemstvo books).