This interesting and unusual surname is a dialectal variant of "Cowperthwaite", itself a topographical name for someone who lived by the Cooper's enclosure. The name itself is composed of "Copper-", from the Medieval English "couper" or "Cowper" (from the Middle Low German "kuper", tub, container) describing someone who made and repaired wooden vessels such as barrels, tubs, buckets and vats, plus the second element "-thwaite", from the Old Norse "thveit", a meadow, piece of land, but in England meaning a piece of land fenced off, an enclosure. Placenames ending in "-thwaite" are usually found in the northern counties of Cumberland, Westmorland and lancashire. Henry Cowperwhait married Catherine Wylde on September 30th 1576, at Dalton in Furness in Lancashire while at the church of St. Andrews, Penrith in Cumberland William, son of Roland Copthwait was christened on July 21st 1577. The church registers of london record the christening of Sarah, daughter of William and Sarah Copperwaite on July 29th 1747. The first recorded spelling of the family name is shown to be that of Agnes Cowpthwate, which was dated March 5th 1568, church records, Priory Church, Cartmel, lancashire, during the reign of Queen Elizabeth 1, "Good Queen Bess", 1558 - 1603. Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.