Newton published it in 1686 in his Philosophiæ Naturalis Principia Mathematica ("the Principia").

Principia mathematica; often referred to as Newton's Principia.

1687! It is also known as the Principia Mathematica.

In his first book, The Principia, Newton defined the three laws of motion that govern the planetary bodies. Isaac Newton was an English physicist.

Isaac Newton wrote Principia Mathematica. The title was also used by Bertrand Russell and Alfred Whitehead for their 20th century work.