The work is a review of the 20th Conference of “Ordines militares” cycle which took place in Torun (Poland) on September 25—28, 2019. The theme of the international forum was “Communication in the Military Orders: Spaces — Structures — Forms”. The review discusses the reports delivered by researchers-medievalists of various countries. A special attention is paid to the history of the conferences of the cycle. “Ordines militares” conferences have been held for 40 years (every two years), and they became a large-scale international forum of medievalists who study military and monastic orders. Delegates from Australia, Corea, Cyprus, the Czech Republic, England, Estonia, France, Hungary, Germany, Israel, Italy, Japan, Lithuania, the Netherlands, Poland, Russia, Spain, the USA, and Wales participated in the last conference.