Editing Leonhard Euler (section)

===Saint Petersburg===
[[File:Euler-USSR-1957-stamp.jpg|thumb|left|1957 [[Soviet Union]] stamp commemorating the 250th birthday of Euler. The text says: 250 years from the birth of the great mathematician, academician Leonhard Euler.]]
Johann Bernoulli's two sons, [[Daniel Bernoulli|Daniel]] and [[Nicolaus II Bernoulli|Nicolaus]], entered into service at the [[Russian Academy of Sciences|Imperial Russian Academy of Sciences]] in [[Saint Petersburg]] in 1725, leaving Euler with the assurance they would recommend him to a post when one was available.{{sfn|Calinger|1996|p=125}} On 31 July 1726, Nicolaus died of appendicitis after spending less than a year in Russia.{{sfn|Calinger|1996|pp=121–166}}<ref name=mactutor>{{MacTutor|title=Nicolaus (II) Bernoulli|id=Bernoulli_Nicolaus(II)|mode=cs1}} Retrieved 2 July 2021.</ref> When Daniel assumed his brother's position in the mathematics/physics division, he recommended that the post in physiology that he had vacated be filled by his friend Euler.{{sfn|Calinger|1996|p=125}} In November 1726, Euler eagerly accepted the offer, but delayed making the trip to Saint Petersburg while he unsuccessfully applied for a physics professorship at the University of Basel.{{sfn|Calinger|1996|p=125}}

Euler arrived in Saint Petersburg in May 1727.{{sfn|Calinger|1996|p=125}}<ref name="zum werk leonhard" /> He was promoted from his junior post in the medical department of the academy to a position in the mathematics department. He lodged with Daniel Bernoulli with whom he worked in close collaboration.{{sfn|Calinger|1996|pp=126–127}} Euler mastered Russian, settled into life in Saint Petersburg and took on an additional job as a medic in the [[Imperial Russian Navy|Russian Navy]].{{sfn|Calinger|1996|p=127}}

The academy at Saint Petersburg, established by [[Peter the Great]], was intended to improve education in Russia and to close the scientific gap with Western Europe. As a result, it was made especially attractive to foreign scholars like Euler.{{sfn|Calinger|1996|p=156}} The academy's benefactress, [[Catherine I of Russia|Catherine I]], who had continued the progressive policies of her late husband, died before Euler's arrival to Saint Petersburg.{{sfn|Calinger|1996|p=126}} The Russian conservative nobility then gained power upon the ascension of the twelve-year-old [[Peter II of Russia|Peter II]].{{sfn|Calinger|1996|p=126}} The nobility, suspicious of the academy's foreign scientists, cut funding for Euler and his colleagues and prevented the entrance of foreign and non-aristocratic students into the Gymnasium and universities.{{sfn|Calinger|1996|p=126}}

Conditions improved slightly after the death of Peter II in 1730 and the German-influenced [[Anna of Russia]] assumed power.{{sfn|Calinger|1996|p=128}} Euler swiftly rose through the ranks in the academy and was made a professor of physics in 1731.{{sfn|Calinger|1996|p=128}} He also left the Russian Navy, refusing a promotion to [[Lieutenant (navy)|lieutenant]].{{sfn|Calinger|1996|p=128}} Two years later, Daniel Bernoulli, fed up with the censorship and hostility he faced at Saint Petersburg, left for Basel. Euler succeeded him as the head of the mathematics department.{{sfn|Calinger|1996|pp=128–129}} In January 1734, he married Katharina Gsell (1707–1773), a daughter of [[Georg Gsell]].{{sfn|Gekker|Euler|2007|p=[https://books.google.com/books?id=Ta9bz1wv79AC&pg=PA402 402]}} [[Frederick the Great|Frederick II]] had made an attempt to recruit the services of Euler for his newly established [[Prussian Academy of Sciences|Berlin Academy]] in 1740, but Euler initially preferred to stay in St Petersburg.{{sfn|Calinger|1996|pp=157–158}} But after Empress Anna died and Frederick II agreed to pay 1600 [[Écu|ecus]] (the same as Euler earned in Russia) he agreed to move to Berlin. In 1741, he requested permission to leave for Berlin, arguing he was in need of a milder climate for his eyesight.{{sfn|Calinger|1996|pp=157–158}} The Russian academy gave its consent and would pay him 200 rubles per year as one of its active members.{{sfn|Calinger|1996|pp=157–158}}