The surname Knowers was first found in 1024, when Gilbert de Noyers witnessed a charter of Duke Richard to Fontanelles. No locations is provided, but it is important to note that this entry was a lifetime (42 years) before the Norman Conquest in 1066.
By the time of the Domesday Book in 1086, "William De Noiers or De Nuers was an under-tenant in Norfolk; and 'the manor of Gothurst, or, as it is now called, Gayhurst in Buckinghamshire was, at the time of the Norman Survey, held under the Bishop of Bayeux by Robert de Nodariis, or Nowers, whose family not long afterwards became possessed of it in their own right.' Almaric de Noers, in the time of Henry III., held one knight's fee of William de Say, 'being (as it may be presumed) the same which Walter Giffard, Earl of Buckingham, 12 Hen. II., then certified that Hugh de Nuers held of him in that county." 
"His son William married the heiress of Stoke-Goldington, and was the father of another Almaric, In 24 Edward I., he was one of those eminent persons who had summons to attend the great council then ordained to assemble at Newcastle-upon-Tyne. In the year following, his name is mentioned as one of the knights of the shire for the county of Bucks, being then written Amary de Nowers. He died 2 Edward II, seized of the manors of Gothurst, Weston, and Stoke Goldington in Buckinghamshire, and of Cestre Parva, in the county of Northampton. Joan his wife died shortly after, 4 Edward II., being then seized of the manor of Lathebury, and of a part of the manor of Cainho, in the county of Bucks." 
The family was shown with several spellings, de Noiers, de Noies, de Nouuers, Noers, Nourse.
"William de Noers of Domesday had the custody of thirty-three of the Conqueror's manors in Norfolk, and is said to have stood high in his favour. Ralph de Nuers held Swanton-Nuers (Nowers) of the Bishop of Norwich, and witnesses a deed of Robert Fitz Ralph in the time of Henry II." 
The first Lord of the manor was Simon de Noers, and he was succeeded by Robert de Nowers, Lord of the manor of Knossington in 1278.
"Nowers or De Nowers was the ancient form of the name, and as such it occurred in the 18th century in Lincolnshire and Bedfordshire. However, it is probable, as Lipscomb points out, that the principal early home of the name was in Buckinghamshire, where the family of De Nowers possessed great influence in the 12th and 13th centuries, being now represented in that county by the later names of Nourse and Nurse."