This group has been created to explore the creation of an inclusive open-source historical mapping community, with a focus on Early Modern London, Early Modern England and Wales, Ireland and Scotland, and their relations with the wider world. It is an initiative of the MarineLives project team. The MarineLives project was launched in 2012 to work collaboratively on the transcription, linkage and enrichment of the legal records of the English High Court of Admiralty. We welcome academics and non-academics to contribute to this group, which is hosted on the Humanities Commons platform, and to advance a culture of exchange of data sets, map layers, polygons, georeferenced data and methodologies.