The paper tries to establish where the medieval craftsmen builders came from and what was their part in the construction of monasteries, paying special attention to the two largest at the beginning of the 13th century -- the monasteries Studenica and Zica. The article deals especially with a group of craftsmen who worked on the parvis and on the towers in Studenica, on the church and parvis of Mileseva and on the bell-tower of the Zica monastery. It is concluded that the Byzantine dome constructions were very well known to them, but that they were trained in the areas conquered by the Roman style. They could originally have come from Kotor or some other town in Zeta and it is possible that they spent their working life in Zica. The article includes 13 black and white photographs in support of the mentioned arguments. -- AATA