In January 1610 (Keichō 15), the site was roped off and work began. Tokugawa Ieyasu ordered various "daimyōs" to help with the construction of what was to become the new capital of the existing Owari Province. Katō Kiyomasa, Fukushima Masanori, and Maeda Toshimitsu were among the 20 feudal lords from the northern and western part of Japan who were assigned to assist in the project. The inscriptions of feudal lords and their vassals, carved on the stones they carried, are still visible today. In August 1610 the stone foundation of the main keep ("tenshu") was completed, and by December construction of the stone walls for the Honmaru, Ninomaru, Nishinomaru, and Ofukemaru buildings was almost finished. In June 1611 (Keichō 16) a canal that today is the Hori River was built. The source for much of the building material for the new castle was the smaller Kiyosu Castle, including its "tenshu", which was rebuilt as the northwest turret. In mid-1612 (Keichō 17), the construction of Honmaru Palace began, and the main keep was completed in December of that year.