Abstract: John Pell (1611-1685) has long been considered the most enigmatic of the 17th-century mathematicians. He was well read in both Classical and contemporary mathematics, and there is no doubt that he was held in esteem. However, attempts to discover just what Pell's mathematical reputation was based on, create a picture that is strangely unclear. His name is linked with the equation Np² ± I = q² (for N, p, q integers), universally known as ‘Pell's equation’ but it was neither proposed nor solved by Pell. His mathematical publications were few and far between: the book for which he is best remembered is An introduction to algebra published in 1668, but other books expected of him failed to appear. There were always hints that he was developing further ideas, but he could never be persuaded to share them.

Keywords: John Pell, mathematician, An introduction to algebra, Wallis,