Robert Recorde (1510-1558), the founder of the English school of mathematics, introduced algebra into England; he is also given credit for the introduction of the equals sign.
Robert Recorde was born in Wales. For a time, he taught mathematics at Cambridge and Oxford universities. He had first attended Oxford but received the medical degree from Cambridge in 1545. He then went to London, where he was court physician to Edward VI and Mary Tudor. The fact that Recorde graduated in medicine and was a practicing physician did not detract him from studies in mathematics; he published four books on that subject and only one on medicine.
Recorde's first book, The Ground of Artes (1540), was very popular. At the time of its publication, England had not made nearly the progress in mathematical books that was typical of the Continent, and his book served, in part, to close the gap. It was intended to be a basic arithmetic but has been described as a book of commercial arithmetic. It went through 18 editions in the 16th century and 12 in the 17th. In the preface Recorde introduces a dialogue between the teacher and the scholar in which the teacher explains the usefulness of arithmetic, mentioning, among other subjects, how much music, physics, and law depend on numbers and proportions. He also lists the number of occupations, such as those of merchant, steward, bailiff, army officer, and treasurer, in which, the master claims, a knowledge of arithmetic is an absolute necessity.
Recorde's other books included The Castle of Knowledge (1551), a work on astronomy which served to bring the Copernican hypothesis to the attention of the English reading public. The Pathewaie to Knowledge (1551) contains an abridgment of Euclid's Elements of Geometry. Of more importance was The Whetstone of Witte (1557), where the modern equals sign first appeared in print. The work also showed methods for extracting roots, the Cossike practice (algebra), the rule of equation, and "the woorkes of Surde [irrational] Nombers."
The Ground of Artes, Recorde's most important book, appeared at a time when commerce and finance were flourishing as never before. The England of Elizabeth I welcomed a book which told its merchants and investors how to compute with both Arabic numerals and with counting machines, how to establish proportions, the methods of fractions, and many other commercial forms and topics which had been established in Renaissance Italy well before Recorde's time.
For a time Recorde held the post of comptroller of mints and monies in Ireland, but his life ended in King's Bench Prison, Southwark, London. It is said that he was in prison for debt, but some evidence indicated that he was involved in a scandal concerning Irish mines.
A biographical sketch of Recorde, as well as a selection from The Ground of Artes, is in James R. Newman, ed., The World of Mathematics, vol. 1 (1956). The older work of David Eugene Smith, History of Mathematics, vol. 1 (1923), gives a concise discussion of English mathematics in the early modern period.