"As the correspondence at the Einstein Archives at Princeton reveals, one of the young scientists deeply caught up in Mach's point of view was Michelange (Michele) Besso—Einstein's oldest and closest friend, fellow student, and colleague at the Patent Office in Bern, the only person to whom Einstein gave credit for help (manche wertvolle Anregung) when he published his basis paper on relativity in 1905. It was Besso who introduced Einstein to Mach's work [Science of Mechanics]. ...Besso remained a loyal Machist to the end."