[Transcribed information from A Topographical Dictionary of England - Samuel Lewis - 1835] (unless otherwise stated)
"BLETSOE, a parish in the hundred of WILLEY, county of BEDFORD, 6 miles (N.N.W.) from Bedford, containing 383 inhabitants. The living is a rectory, in the archdeaconry of Bedford, and diocese of Lincoln, rated in the king's books at £17, and in the patronage of Lord St. John. The church is dedicated to St. Mary. The river Ouse runs through the parish, in which are the remains of an ancient castle, formerly belonging to Lord Bolingbroke, part of which has been destroyed for the materials. Here is a mineral spring, but the water is seldom used medicinally."