Leonhard Euler was by far the best mathematician of the 18th century. His contributions to mathematics range from common notation to the proof of Newton's and Leibnitz's hypothesis. His discoveries cannot be limited to a single area of ​​interest, nor to the field of mathematics alone. He made great progress in geometry, calculus, trigonometry, algebra and number theory, as well as in continuum physics, lunar theory and other areas of physics. He is also one of the best-written mathematicians whose works could be contained in 60 to 80 quarto volumes. Probably the most extraordinary fact about him is that the majority of his work took place during the last twenty years of his life, when he was completely blind. Euler is undoubtedly one of the greatest mathematicians of all time. Leonhard Paul Euler was born the son of a pastor on April 15, 1707 in Basel, Switzerland. Shortly after his birth, his family moved to Riehen, where Leonhard would spend most of his childhood. Leonhard's father, Paul, was a good friend of the Bernoulli family, whose patriarch, Johann Bernoulli, was then considered the greatest mathematician in Europe. Bernoulli would ultimately become a great influence on Leonhard's life. When Leonhard was thirteen, he was sent to live with his maternal grandmother in Basel, where he enrolled at the University of Basel and eventually earned his master's degree in philosophy and wrote his thesis comparing the philosophies of Newton and Descartes. Euler followed in his father's footsteps, studying theology, Greek and Hebrew, and was determined to become a pastor. However, Johann Bernoulli was convinced that Euler was destined to become a great mathematician and convinced Paul Euler to let his son pursue his own passion... middle of paper ... he was virtually blind. This failure did not slow him down as he managed to publish the majority of his work at this stage of his life, which is truly astounding. He got through it thanks to a phenomenal memory, advanced mental arithmetic skills and the help of scribes. Euler was truly unstoppable in the field of mathematics. As you can see, Euler contributed a lot to the world of mathematics. From developing important notations, formulas, and constants to demonstrating formulas and equations that baffled most other mathematicians of his day, there was almost nothing he couldn't do that involved mathematics. He was instrumental in developing the future of modern mathematics and is credited with helping to develop pre-calculus, calculus and differential equations. Although not a household name, he is quite easily the greatest mathematician who ever lived..