 Brunn studied archaeology and philology at the University of Bonn, where he was influenced by the teachings of Friedrich Gottlieb Welcker (1784-1868) and Friedrich Ritschl (1806-1876).In 1843 he received his doctorate degree with the work "Artificum liberae Graeciae tempora", afterwards moving to Rome, where for several years he was associated with the German Archaeological Institute (DAI).In 1853, he received an appointment at Bonn, but within a few years, returned to Rome as second secretary of the DAI, serving under Wilhelm Henzen (1816-1887).