Question: What was Droysen's work called that explained the era?
Sentence: Although words related in form or meaning, e.g. Hellenist (Ancient Greek: Ἑλληνιστής, Hellēnistēs), have been attested since ancient times, it was J. G. Droysen in the mid-19th century, who in his classic work Geschichte des Hellenismus, i.e. History of Hellenism, coined the term Hellenistic to refer to and define the period when Greek culture spread in the non-Greek world after Alexander’s conquest.
Answer in sentence: yes