The original version of the physical discipline of mechanics, due to Sir Isaac Newton, who developed the theory over a period from about 1664, until the publication of his great work, known as the "Principia", in 1687.
While Newton chose to present the work in classical geometric form, for acceptance, much of the foregoing development of the theory was actually based on his invention of the calculus of infinitesimals, as a new discipline of mathematics. It was eventually in this form, which laid the foundation of so much of todays science and mathematics, along with the differential calculus of G.W. von Leibniz, that Newtonian mechanics evolved into the theory of classical mechanics. This development, over two centuries, was due to a great many scientists, including L. Euler, J.L. Lagrange, P.S. de Laplace, W.R. Hamilton, C.G. Jacobi, and countless others.
References
Js. Newton, Philosophiae Naturalis Principia Mathematica, London 1687. Transl. by A. Motte (1729), and F. Cajori: Sir Isaac Newton's Mathematical Principles of Natural Philosophy and his System of the World, University of California Press, Berkeley 1934.
Richard S. Westfall, Never at rest, A biography of Isaac Newton, Cambridge U. Press 1980.