The man who was partially credited for developing the infinitesimal calculus was the seventeenth century English mathematician. He was appointed by the Parliament of Britain as the chief cryptographer of the royal court. Moreover, he is recognized for creating the infinity symbol in mathematics.

John Wallis was born on 3 December, 1616 in Ashford, Kent, England, to a reverend. He received his early education from a local Ashford school. Following an outbreak of plague in 1631, he moved to James Movat’s school. He also attended Martin Holbeach’s school in Felsted where he was introduced to the discipline of mathematics. He was fascinated by the subject but studying mathematics was not taken as seriously back then. It was considered more of a mechanical subject rather than an academic one.

Wallis’ family expected him to become a doctor and in order to fulfill their wishes he attended Emmanuel College, Cambridge in 1632. Despite having been trained in medicine, his main focus remained mathematics. In 1637, he earned his Bachelor of Arts and a Master’s in 1640. Afterwards, he joined the priesthood and served as a nonvoting scribe at the Westminster Assembly in 1640s. Queens’ College, Cambridge offered him a fellowship in 1644. He remained involved with the Parliamentarian party, through the span of his life. He was the chief cryptographer with the Royal Court who encoded and decoded messages. One of the most used ciphering techniques at that time was were ad hoc methods based on secret algorithm. Even Wallis preferred that method because it was unbreakable. He was untrusting of the use of ciphers by foreign powers. In fact, he refused the request to teach Hanoverian students about cryptography.

Wallis had been made chaplain upon his return to London and stayed in the company of scientists that later laid the foundation of Royal Society in England. He kept practicing mathematics despite his other involvements. He mastered William Oughtred’s Clavis Mathematicae and afterwards began to write treatises. There were various topics on which he wrote. The Oxford University appointed him to the Savilian Chair of Geometry in 1649. Additionally, at the Savoy Conference he represented Presbyterian party.

Besides mathematics, he touched upon multifarious subjects as topics of his writing. Those array of disciplines include philosophy, logic, theology and English grammar. Furthermore, he worked on a system to teach the deaf and mutes. Wallis once falsely claimed the credit for rendering a deaf man to speak which was actually accomplished by William Holder. In 1695, Wallis wrote *Opera Mathematica*, in which he discussed trigonometry, geometry and calculus. He rejected the concept of negative number which is vital in the modern mathematics. Despite his shortsightedness in this area he was credited for originating the notion of number line.

In his prominent work, *Treatise on the Conic Sections,* the symbol of infinity was introduced. In his salient and noteworthy treatise, *Arithmetica Infinitorum,* he systematized the methods of analysis of Cavalieri and Descartes. His *Algebra* which sheds the light on the historical development of the subject, was published in 1685. He was highly influenced by the Muslim mathematician Sadr al-Tusi and his works. Wallis found al-Tusi’s book on the parallel postulate quite inspiring. Latin works of Ptolemy, Porphyrius and Bryennius were translated by Wallis. In 1687, he published *Institutio logicae* on logic and on English grammar he wrote, *The Grammatica linguae Anglicanae*.