Old, was formerly a parliamentary borough of England, in Wiltshire, 2 miles N. of Salisbury; returning two members to parliament, though without a single house or inhabitant. It was thus, before the Reform Act of 1832, by which it was disfranchised, the most complete instance of a rotten borough. The place is, however, of great antiquity, having existed, under the name of Sorbi-odunum, in the time of the Romans. It was fortified by Alfred, and after the Norman Conquest was made the seat of a bishop. The cathedral was removed in 1220, in consequence of a quarrel between the bishop and the people, to Salisbury, or New Sarum; and from that time Old Sarum began to decline. Some remains of walls and ditches still exist.