The surname of LAMBART was an occupational name - the lamb-herd - one who kept charge of the sheep, a shepherd. In the small villages of Europe, many occupations gave rise to the name of the original bearer. Many modern family names throughout Europe reflect the profession or occupation of their forbears in the Middle Ages and derive from the position held by their ancestors in the village, noble household or religious community in which they lived and worked. The addition of their profession to their birth name made it easier to identify individual tradesmen and craftsmen. As generations passed and families moved around, so the original identifying names developed into the corrupted but simpler versions that we recognise today.
Early records of the name mention Johannes de Lamehirde, 1310 Wiltshire. Johannes Lambherd of Yorkshire was listed in the Yorkshire Poll Tax of 1379. Agnes Lambertson listed in the Wills at Chester, in the year 1680. A notable member of the name was John Lambert (1619-84) the English parliamentary soldier, born in Catton, near Settle in Yorkshire, He studied at the Inns of Court, but on an outbreak of the Civil War in 1641, he became a captain under Thomas Fairfax, and at Marston Moor led a cavalry. He helped Cromwell to crush the Scots under James, 3rd Marquis of Hamilton, and captured Pontefract Castle in March of 1649. He suppressed the Royalist insurrection in Cheshire in August 1659, and virtually governed the country with his offices as the 'committee of safety'. Eventually he was sent to the Tower, tried in 1662, and kept prisoner until his death. The associated arms are recorded in Sir Bernard Burkes General Armory. Ulster King of Arms in 1884. In many parts of central and western Europe, hereditary surnames began to become fixed at around the 12th century, and have developed and changed slowly over the years. As society became more complex, and such matters as the management of tenure, and in particular the collection of taxes were delegated to special functionaries, it became imperative to distinguish a more complex system of nomenclature to differentiate one individual from another.