Henzen studied from 1836 to 1840 at the Universities of Bonn and Berlin philology and in 1840 received his doctorate with a thesis on Polybius. Then he traveled to Italy and Greece and archaeological research in 1843, second, by Emil Braun's death in 1856 the first secretary of the German Archaeological Institute in Rome. Since 1853 he was a corresponding member of the Royal Prussian Academy of Sciences, since 1876 member of the Accademia dei Lincei.
Henzen has made high outstanding contribution to Latin epigraphy. After various individual studies he published in 1856 a supplementary volume to Johann Caspar von Orellis Inscriptionum Latinarum collectio. He was with Theodor Mommsen and Giovanni Battista de Rossi since 1853 Member of the editorial team for the published by the Berlin Academy Corpus Inscriptionum Latinarum. Henzen gained the city of Roman inscriptions and published for the first volume, containing the inscriptions until the death of Gaius Julius Caesar, the fasti consulares and Triumphalakten. Along with Eugen Bormann and Christian sleeves he was editor of Parts 1 to 3 and 5 of the 6 band with the urban Roman inscriptions of the imperial period (1876 ff.) Outside the Corpus Henzen published the records of the Fratres Arvales, also many contributions to periodicals and collections, Epigraphica particularly to the Bullet Tino and the Annali of the Archaeological Institute, as well as to the Ephemeris. Corporis inscriptionum Latinarum supplementum.
- Vol 6 of the Corpus Inscriptionum Latinarum, Berlin 1876 ff
- Supplementary volume to Orellis Inscriptionum Latinarum collectio, Zurich 1856.
- Scavi nel bosco dei fratelli Arvali, Rome 1868.
- Acta fratrum Arvalium, quae super sunt, Berlin, 1874.