Although Euler had been charmed at fi rst with his life in Berlin , far from the intrigues of the Russian court, he soon realized that working with Frederick the Great was problematic. If Frederick the Great had been able to accept Euler as a scholar whose daily life was irrelevant to their relations, Euler might have continued happily in Berlin for many years. However, during his 25 years in Prussia’s capital, Euler was repeatedly annoyed by Frederick ’s attitude toward him. His monarch viewed Euler —without a doubt Europe’s most distinguished mathematician-as little more than a lowborn, common peasant who happened to be good with numbers. Frederick knew that Euler had accomplished many impressive things for him, but the fact remained that Euler was totally unsophisticated in his tastes. For example, Frederick could not understand why the man still preferred to speak German although he could easily have switched over to the elegant French language! Frederick was dismayed by Euler ’s openly devout lifestyle, in which he displayed a humility that was incompatible with the fashions of Frederick ’s royal court. By now, these two remarkably capable men, who were in fact dependent on each other in many ways, had lost any mutual ground. To Euler , St. Petersburg looked better and better.