CASAL, a strong town of Italy in Montferrat, with a citadel and a bishop's see. It was taken by the French from the Spaniards in 1640; and the duke of Mantua sold it to the French in 1681. In 1695 it was taken by the Allies, who demolished the fortifications; but the French retook it, and fortified it again. The king of Sardinia became master of it in 1706, from whom the French took it in 1745; however the king of Sardinia got possession again in 1746. It is seated on the river Po, in E. Long. 8. 37. N. Lat. 54. 7.