The paper examines the chronology of the campaign of the Hungarian palatine William Druget in the Galicia - Volynia principality of 1340. Being the cousin and ally of the Polish king Casmir III the Great, Hungarian King Charles Robert of Anjou in order to obtain the aforementioned Russian lands after the death of their ruler Yuri II Boleslav, undertook this campaign as a military aid to the Polish ruler. In addition, the author of the paper tries to determine the length of the Hungarian war on Russian soil, and possible strength of the Hungarian royal army under the command of one representative of the family Druget. Drugets were in fact, in previous decades commanders of the army in campaigns against Serbia, Croatia, and Prussia. Based on the analysis of data from published itinerary court charters, as well as from the itinerary of the Palatine himself, author of the paper comes to the following conclusion. The operation of the Hungarian army in Ruthenia, which was led by William Druget, had most likely started after 1 May 1340 (date post quem, most probably between 1 and 8 May) and the Druget returned to Visegrad before 11 June (date ante quem). If we reject the necessary days needed for Hungarian troops and their chambers to go and to safely return through the Carpathian Mountains, one can cautiously assume that Druget in Galicia could have actively been at war for about ten days. Considering the territory in northeastern Hungary which Druget family had ruled over and experience of their warriors, as well as the sporadically preserved names of possible participants in this campaign, it can be concluded that the army sent „in Ruthenia“ had represented a significant military force.
