This repository contains various data related to my dissertation: Visser, RM. 2025. Relating Roman Rings. An interdisciplinary study using archaeology, data science and tree rings to understand timber provision in the German Provinces of the Roman Empire. PhD Thesis. Amsterdam: Vrije Universiteit. DOI: https://doi.org/10.5463/thesis.1062. The data consists of CofechaOutputSiteChronologies.zip: the COFECHA output of site chronologies created. A description how to read these outputs can be found here: https://sheppard.ltrr.arizona.edu/DISC2019/cofecha.txt. See also: Holmes, RL. 1983 Computer-assisted quality control in tree-ring dating and measurement. Tree-Ring Bulletin 43: 69–78. for more explanation. series_with_series.csv: a table with all comparisons of individual tree-ring series. The table structure is found in series_with_series.sql with the SQL-statement to create a PostgreSQL-table. mean_with_mean.csv: a table with all comparisons of individual tree-ring series. The table structure is found in mean_with_mean.sql with the SQL-statement to create a PostgreSQL-table. sites_wkt.csv: a table with the coordinates of each site and the number of (dated) samples site_chronologies_metadata.csv: a table with all site chronologies and the dates and locations Figures.zip: all figures in the dissertation Tables.zip: all tables in the dissertation as csv-file These are part of the appendices of the dissertation, but not all are printed in the book/PDF.