This is an English compound surname of medieval origins. Normally it is residential for a person who lived at a place called Rockwell, Rookwood or Rockwood. Rockwell, in the county of Buckinghamshire, derives from the Old English pre 7th century "hroc", meaning a rook, and perhaps "hol", meaning a hollow, whereas Rockwell Green in Somerset has "wealla", meaning a stream as the second element. Rockwood is a 'lost' medieval village in West Yorkshire, whilst Rookwood is a part of Cardiff in Wales. The more unusual surnames Rooker, Rookherd and Rookyard, as in Henry le Rocharde of Oxfordhsire in 1273, are believed to be occupational, and to describe a person who was a keeper of rooks, or of the place (yard) where they were kept. 'Rook and blackbird' were a popular dish in past times, and these birds were bred for the table just like other fowl. Amongst the sample recordings are those of Edmund Rockwoode who marrried Elenor Groundich (!) at St Giles Cripplegate in the city of London on May 30th 1579 and the christening of Gratia Rockwell on June 3rd 1586 at Hughenden, in Buckinghamshire.Surrnames became necessary when governments introduced personal taxation. In England this was sometimes known as the Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.