After the eleventh century, as masonry techniques advanced, ashlar blocks became more rectangular, resulting in more stable walls that could incorporate refined architectural moulding and detailing that can be seen in corbelling, buttressing, lintels and arching. At the same time there was increasing influence from English and continental European designs, known as Romanesque. The Romanesque style had its origins in Roman building techniques and early churches in the Byzantine Empire and Italy and was characterised by massive reinforced walls and round arches that could bear the weight of rounded barrel vault roofs. The introduction of this style to Scotland is associated with the ecclesiastical reforms that began in the reign of Máel Coluim III (r. 1058-93), bringing continental ideas of monasticism and church organisation to the country. The oldest Romanesque church in Scotland is probably the small chapel built for Máel Coluim's wife Margaret on Castle Rock, Edinburgh, with a vaulted semi-circular apse. In the twelfth century a number of new parish churches were built by lords on their land. They were often small aisless buildings with two or three connected cells, each of diminishing size, ending in a rounded apse. One of the best preserved is at Dalmeny in Lothian.