The development of the radiocarbon (14C) dating technique represents one of the most significant events in the history of archaeological thought; with this innovative method archaeology really started again in the 1950s. Identifying when things happened in time (as well as where things happened in space) is central to the archaeological endeavour. Since the 1950s millions of pounds/euro have been spent in Ireland and the UK producing 14C measurements in order to undertake archaeological research. These measurements have been funded by government heritage agencies, by academic researchers, by archaeologists in professional practice, by local societies, and by research agencies including the IRC and the AHRC. The numbers of these data have significantly increased in the UK with changes in central planning policy, from Planning Policy Guidance 16 onwards and with the development of professional archaeological practice as part of the construction industry. In the Republic of Ireland, the construction boom associated with the 'Celtic Tiger' economy had a similar impact on the scale of the production of 14C data. The rapid expansion in the numbers of 14C data also underlines how central they are to all forms of archaeology, produced from every type of archaeological site, from the whole 60,000 years of human history when the technique can be used. However, 14C data can only be used effectively in subsequent research if they are correctly reported (Bayliss 2015; Millard 2014); because of a lack of training across the sector essential data attributes are often not reported or made publuc by researchers. If these attributes are lost or removed from radiocarbon measurements their utility becomes compromised and their value lessened. Ironically, given the importance of these data, there has been a global failure to curate them effectively. Across the UK and Ireland, there is no single functioning 14C archive. Because of this, millions of euros/pounds of data are being made rogue - with inaccurate, incomplete, or otherwise compromised 14C attributes often present in research literature. Moreover, the absence of international digital archives for these essential data is a significant barrier to research that seeks to work across national historic environment agency jurisdictions. This has major issues globally for archaeological research, and is especially true for Ireland and the UK, where many research objectives exist across borders, with datasets that do not respect the confines of contemporary nation states. Further, reporting standards mean that many existing 14C data are not interoperable with existing historic environment data management systems. The result is that we are impoverishing vast quantities of data of huge value, and that our research into, analyses of, and curation of the historic environment are similarly compromised. This project will address this significant, international problem for all archaeological research periods by transforming available data from across Ireland and the UK, reconstituting the essential attributes, and safeguarding these data for the future. We will use these data to achieve innovative Big Data analyses into the management of the historic environment, and into archaeological research across all periods and regions of the UK and Ireland. Our lasting legacy will be making these data and our analyses discoverable, open access, sustainable and functional for researchers to come, providing a sector-wide training legacy, and developing schools resources to educate the next generation of digital humanities researchers in the historic environment. We are supported in this work by our historic environment partners in national government, and national heritage agencies, and the digital infrastructure provided by the Archaeology Data Service which will secure this invaluable resource for the future.