This paper presents an exploratory case study of definitions, or assertions, of the Iron Age and its subdivisions consisting of name, date range, location, and source within two broadly defined geographic regions. The collected assertions represent a period label-the Iron Age-that would appear in an authoritative database of time periods that does not require a controlled vocabulary. Assertions were gathered from archaeological literature and related sources. Results showed that date ranges for the Iron Age varied both by region and scholar. Subdivisions within the Iron Age are also named differently depending on the geographic area. Consolidating definitions for an authority file would cause loss of information. This study is intended to address the role of authority files in temporal metadata in order to contribute generally to an understanding of appropriate metadata.