At least as early as in the 1330s, the position of ‘master mason’ (‘magister lapidum’; ‘magister laterum’, ‘steinmeister’, ‘czygelmeyster’, ‘muwermeister’) was established in the Teutonic Order’s state in Prussia in order to coordinate works on either the construction or development of brick castles. A Teutonic Order’s knight as a master mason had to accomplish a given construction assignment. The scope of his duties covered hiring professional individuals and labour force (and this also included paying wages, providing food and accommodation), supervising work performance, buying limestone, lime, timber, ropes for scaffolds, tools, bricks, nails as well as organising transportation. The most significant element of this research analysis is recognising an explicit correlation between the position of ‘master mason’ (always appointed for a specified period of time) and building brick castles. This fact allows to specify the chronology of erecting selected castles. It was possible to ascertain that the construction of the high castle in Ragnit (Neman) was finished immediately before 1406, and the two stages of developing the capital castle fortress in Marienburg (Malbork) occurred in the 1340s and 1370s. As far as Danzig (Gdansk) is concerned, it was found that the local castle was erected in the second half of the 1330s, it was developed in 1350s, and it was reconstructed after fire destruction at the end of the 14 th and in the beginning of the 15 th centuries. In the case of other brick castles (not only commander castles), the findings corroborate claims that castles were built in the following periods of time: Schlochau (Czluchow) – the second half of the 1340s, Tuchel (Tuchola) – mid-1350s, Lauenburg (Lebork) – early 1360s, Barten (Barciany) – 1377–1384, Labiau (Polessk) – 1386–1391, Neidenburg (Nidzica) – 1407–1409, and finally, Memel (Klaipėda) – the second half of the second decade of the 15 th century.