The town is supposed to derive its name from Theoc, a Saxon monk, who founded a hermitage here in the end of the 7th century, which was changed into a monastery by the duke of Mercia in 715, and rebuilt by Sir Robert Fitz-Hamon in 1102. On the death of Fitz-Hamon in 1147 the manor passed to the De Clares, who became merged in the De Spensers, they in turn in the Beauchamps, and the Beauchamps in the Nevilles. At Tewkesbury took place, 4th May 1471, the battle between the Yorkists and Lancastrians which placed the crown on the head of Edward IV. During the Civil War the town was occupied by the Parliamentarians, who were driven out by the Royalists; but it was surprised and captured by the former in 1644, after which it remained in their possession. Tewkesbury was first incorporated by Elizabeth in 1574, and when James I. sold the manor to the corporation in 1609 he granted it a new charter with extended privileges. This being lost during the Civil War, a new charter was granted by Charles II. Between 1692 and 1698 the town was without a corporation, but a new charter was granted by William III., which remained the governing charter until the passing of the Municipal Act. Until 1867 Tewkesbury returned two members to the House of Commons; from 1867 to 1885 it returned one; and in 1885 it became merged in the north or Tewkesbury division of Gloucestershire.
The Annales de Theokesberia (1066-1263) are published in Annales Monastici, edited by H. R. Luard, 1864.