Book dealer and architectural historian. Nagler earned his doctorate from the Universität Erlangen in 1829. Through his research at the Bayerische Staatsbibliothek in Munich, he completed his first major scholarly reference publication, Neues allgemeines Künstler-Lexicon (1835-52). It took Nagler seventeen years, scrupulously delivering a manuscript every month to his printer, E.A. Fleischmann, in Munich. Comprehensive art dictionaries and encyclopedias were only then being written. Scholars had mixed feelings about such works.