images was carried out by the institutions they belonged to, the council itself, churches and the guilds. Some images were sold rather than destroyed, but most seem to have been lost. By the summer of 1584 Antwerp was besieged by the Duke of Parma's Spanish army, falling a year later. Artistic losses Rarely was any thought given to the artistic heritage of these cities in 1566, though families were sometimes able to protect the church monuments of their ancestors, and in Delft the syndics of the painters' Guild of Saint Luke were able to rescue the altarpiece by Maarten van Heemskerck, which the guild had commissioned only 15 years earlier. The van Eycks' Ghent Altarpiece, then as now famous as a supreme example of Early Netherlandish painting and already a major tourist attraction, just restored in 1550, was saved by dismantling it and hiding it in the cathedral tower. A first attack on 19 August was deterred by a small number of guards. When a larger attack was made at night two days later the iconoclasts had provided themselves with a tree trunk as a battering ram, and succeeded in breaking through the doors. By then the panels had been removed from the frame and hidden, with the guards, on the narrow spiral staircase up the tower, with a locked door at ground level. They were not detected and the crowd left after destroying what else they could find. The panels were then moved to the town hall, and only returned to view in 1569, by which time the elaborate frame had disappeared. The artistic and literary losses were elaborately described by Marcus van Vaernewyck in his journal Van die beroerlicke tijden in die Nederlanden en voornamelick in Ghendt 1566-1568. The original manuscript of his journal is still preserved in the Ghent University Library. Despite militia guards, two of the three main churches in Leiden were attacked; in the Pieterskerk the choirbooks and altarpiece by Lucas van Leyden were preserved. In the Oude Kerk in Amsterdam an altarpiece with a central panel by Jan van Scorel and side panels painted on both sides by Maarten van Heemskerck was lost. The most important works of several painters, especially those like Pieter Aertsen who worked in Antwerp, were all destroyed, leading to a somewhat distorted view of the art history of the period. An altarpiece in Culemborg had been commissioned in 1557