Mariusz Balcerek, PhD, works in the Department of Information and Bibliography in the Copernicus Regional Public and Municipal Library in Toruń. His research interests focus on military history of the Early Modern period (the 16th–18th centuries). In 2010 he defended the doctoral thesis in the Institute of History and Archival Studies of Nicolaus Copernicus University in Toruń. The title of thesis was The Duchy of Courland and Semigallia during the war between Poland and Sweden in the years 1600–1629, Poznań 2012), supervised by Prof. dr hab. Bogusław Dybaś. He published in the following journals: ‘Do szarży marsz, marsz… Studia z dziejów kawalerii’, ‘Przegląd Historyczny’, ‘Studia i Materiały do Historii Wojskowości’ and ‘Zapiski Historyczne’. Since 2011 he has been the editor-in-chief of ‘Folia Toruniensia’ responsible for the content of the journal.