Dor'chester, a municipal borough, the county town of Dorsetshire, on the Frome, 8 miles N. of Weymouth, and 110 by rail (by road 119) WSW. of London. Till 1867 it returned two members to parliament, till 1885 one. It carries on a trade in ale and beer, cattle, cereals, and butter; and has a free grammar-school (founded 1579), a county museum, a guildhall (1848), a corn exchange (1867), and a bronze statue (1889) of the Dorset poet, the Rev. W. Barnes. Pop. (1841) 3249; (1901) 9458. Dorchester was the Roman Durnovaria or Durinum, a walled town with a fosse, and a chief Roman British station. Part of the wall, 6 feet thick, still remains. Near Dorchester are the remains of the most perfect Roman amphitheatre in England, 218 by 163 feet, and 30 feet deep, the seats cut In the chalk for 13,000 spectators; as also a Roman camp, and a large British station with three earthen ramparts, l 1/2 mile in circuit, and pierced by intricate passages, and enclosing barrows. The inner rampart is 60 feet high. It is supposed that this great camp, one of the largest in the kingdom, was the Dunium of Ptolemy and the origin of Dorchester. In 1645 Cromwell made the town his headquarters, and in 1685 Judge Jeffreys held his 'bloody assize' here, and sentenced 292 rebels to death.
Dorchester, an Oxfordshire village, 9 miles SE. of Oxford, was the seat of the Mercian bishops from the 7th century till 1073, when the see was transferred to Lincoln. Its Augustinian abbey church (mainly 13th century) is lavishly ornamented. Pop. of parish, 852. See J. H. Parker's History of Dorchester (1882).