Columnarium
Columnarium a tax imposed in the time of Julius Caesar upon the pillars that supported a house. (Cic. ad Att, 13.6) It was probably imposed by the lex sumtuaria of Julius Caesar, and was intended to check the passion for the building of palaces, which then prevailed at Rome. The Ostiarium was a similar tax. [OSTIARIUM] The columnarium levied by Metellus Scipio in Syria, in B.C. 49-48, was a tax of a similar kind, but had nothing to do with the tax to which Cicero alludes in the passage quoted above. This columnarium was simply an illegal means of extorting money from the provincials. (Caes. B.C. 3.32.)
From William Smith (ed.), Dictionary of Greek and Roman Antiquities. Text provided under a CC BY-SA license by Perseus Digital Library, http://www.perseus.tufts.edu, with funding from the National Endowment for the Humanities and Tufts University. Data accessed from https://github.com/PerseusDL/canonical-pdlrefwk/ on 17 October 2026.