Johan Östling’s Humboldt and the Modern German University has been translated from Swedish into English. Even better, this Lund University Press publication is OpenAccess and can be downloaded as a PDF.
From the abstract:
By combining approaches from intellectual history, conceptual history and the history of knowledge, the study investigates the ways in which Humboldt’s ideas have been appropriated for various purposes in different historical contexts and epochs. Ultimately, it shows that Humboldt’s ideals are not timeless—they are historical phenomena and have always been determined by the predicaments and issues of the day.