Leonhard Euler was born in Basel to Paul Euler, a pastor, and Marguerite Brucker. His father had studied mathematics under Jakob Bernoulli and provided young Leonhard's first mathematical instruction.

At just 13, Euler enrolled at the University of Basel, initially to study theology and follow his father's wishes. However, Johann Bernoulli recognized his exceptional mathematical talent and became his mentor.

Euler completed his Master's degree with a dissertation comparing the philosophies of Descartes and Newton. Johann Bernoulli convinced his father to let him pursue mathematics instead of the ministry.

Euler published his first mathematical paper on the optimal placement of masts on ships. Though he didn't win the Paris Academy prize, his entry received honorable mention, marking the start of his prolific publishing career.

Euler accepted a position at the newly founded St. Petersburg Academy of Sciences, initially in the medical department. He soon transferred to mathematics, beginning his rise to become the most productive mathematician in history.

Following Daniel Bernoulli's departure, Euler became the senior chair of mathematics at the Academy. He produced groundbreaking work in mechanics, number theory, and mathematical analysis during this period.

Euler married Katharina Gsell, daughter of a Swiss painter working in Russia. Their happy marriage produced thirteen children, though only five survived to adulthood. Katharina was his devoted partner for forty years.

After an intense period of work, including solving a complex astronomical problem in three days that others estimated would take months, Euler lost sight in his right eye. He reportedly said he now had fewer distractions.

Euler solved the famous Seven Bridges of Königsberg problem, proving it was impossible to cross all bridges exactly once. This solution laid the foundations for graph theory and topology.

Euler accepted Frederick the Great's invitation to join the Berlin Academy of Sciences. He would spend 25 productive years there, writing hundreds of papers while also serving the Russian Academy remotely.

Euler published 'Introductio in analysin infinitorum,' establishing analysis as an independent mathematical discipline. This foundational text introduced the function concept and much modern mathematical notation.

Euler published his comprehensive textbook on differential calculus, systematizing the field and introducing much of the notation still used today, including the symbols for functions, sums, and the base of natural logarithms.

After disagreements with Frederick the Great, Euler accepted Catherine the Great's invitation to return to St. Petersburg with a generous pension. He was warmly received and given one of the finest houses in the city.

A cataract in his left eye left Euler almost completely blind. Remarkably, his mathematical productivity actually increased, as he dictated his work to assistants and performed complex calculations mentally.

A fire destroyed Euler's home and nearly took his life. Though he lost many possessions and manuscripts, he was rescued by a servant. Catherine the Great immediately provided funds to rebuild his home.

Euler's beloved wife Katharina died after forty years of marriage. Three years later, he married her half-sister Salome Abigail Gsell to maintain his household and care for his needs in blindness.

Even in his final year, the blind Euler continued his prodigious output, calculating the orbit of Uranus and working on problems in balloon flight. He produced about 50 pages of mathematics per week until his death.

Euler died suddenly from a brain hemorrhage while discussing the newly discovered planet Uranus. He left behind over 800 published works, with many more published posthumously. He remains the most prolific mathematician in history.