The Mudéjar population brought its technical expertise, most of which dated back to Antiquity, to the Christian society accommodating it. The importance of the professions undertaken by Mudéjars made them significant players in the economic development of the kingdoms on the peninsula, and this ensured that they left a mark on the regulations governing the trades and professions which date from this time. The Mudéjars excelled in the professions relating to construction, especially bricklaying and plasterwork. Once a building's foundations were laid, bricklayers would erect the basic structure before the plasterers applied a finish to the walls. Mudéjars were also skilled carpenters, metalworkers, potters and weavers.