He was the eldest son of Thomas Roper of Heanor, Derbyshire, by his second wife, Anne, daughter and co-heir of Alvered Gresbrooke of Middleton, Warwickshire.
He assisted Dugdale in his history of the county, making investigations which resulted in the discovery of foundations of old walls and Roman bricks.
Roper also had chambers in Lincoln's Inn, and there Dugdale first met in 1638 Roger Dodsworth, his future collaborator in the Monasticon Anglicanum.
Roper worked out the genealogy of his own family, and his pedigree fills several pages in the Visitation of Derbyshire of 1654.
It is illustrated by extracts from deeds, and drawings of seals; but the proofs are usually taken from private muniments, which are seldom corroborated by public records.