He was something of a pioneer for what became an important post-war historiographical approach, respected among historians, in particular, as an authority on the Ottonians and their times, both during his life and for many years following his death.
[7] Holtzmann's father taught at the university of Straßburg between 1874 and 1904, and it was in Strasbourg – between 1871 and 1918 a German city - that the boy grew up and received his schooling.
[1] After a period of recovery, by the end of 1916 Holtzmann joined the staff as a Professor of History at the University of Breslau (as Wrocław was known before the ethnic cleansing of 1944/45).
[1][12] For the final part of his career, between 1930 and his retirement in 1939, he was employed as an ordinary (i.e. full) professor at the Friedrich Wilhelm University (as the “Humboldt” was known before 1945) in Berlin.
[14][15] Holtzmann's principal research focuses included the relations between the German medieval state and the surrounding territories, Franco-German relations during the later Middle Ages as France began to develop towards a more centralised power structure, the ”Ostsiedlung” (west-east colonisation of central Europe in the medieval centuries) and historical sources for the Ottonian period.
[1] In 1935, under the auspices of the “Monumenta Germaniae Historica” project, he produced a new edition of “Die Chronik des Bischofs Thietmar von Merseburg und ihre Korveier Überarbeitung” ("Thietmari Merseburgensis episcopi Chronicon"), originally authored by the tenth/eleventh century Prince-Bishop Thietmar of Merseburg, recognized then and now as a key source for teachers and students of the Ottonians.
[1][16][17] In 1938 he took over as series editor for what was still known as Wattenbach's “Deutschlands Geschichtsquellen im Mittelalter bis zur Mitte des XIII Jahrhunderts”, a directory produced of sources for Medieval German History intended for historians at all levels of scholarship [3] Holtzmann's best known work today is probably his “Geschichte der sächsischen Kaiserzeit 900–1024”, first published in 1941 and still a standard work on the Ottonians three decades later.