 Baumgarten was the son of a Pietist minister from Berlin, but was orphaned by the time he was eight. He followed his older brother Jacob Sigismund (who would become a prominent theologian and historian of religion) to Halle when he was thirteen. The Baumgartens thus arrived in Halle just after Wolff had been expelled and the study of his philosophy banned, although the ban was less strictly enforced at the famous Pietist orphanage and school in Halle (the Franckesche Stift) where they went first than at the university. The younger Baumgarten started at the university at sixteen (in 1730), and studied theology, philology, poetry, rhetoric, and philosophy, especially Leibniz, whose philosophy unlike that of Wolff had not been banned. He began teaching there himself in 1735, upon the acceptance of his thesis on poetry, and published his Metaphysics in 1739. In 1740, the same year as he published his Ethics, he was called to a professorship—or more precisely, ordered to accept it—at another Prussian university, in Frankfurt an der Oder. Georg Friedrich Meier (1718–1777), who had been studying with Baumgarten, took over his classes and was himself appointed professor at Halle in 1746.