Hertford (7), the county town of Hertfordshire, on the Lea, 26 m. N. of London; some few remains of its famous 10th-century castle still exist, and there are several charity schools, a castle built in James I.'s time, and a branch of Christ's Hospital (London); the chief trade is in corn, malt, and flour; in the vicinity is Haileybury College (q. v.).