It varies by dataset, but here are examples for some of the biggest datapoints:
Financials: go back to 2005 and are comprehensive from 2011 onwards for UK companies
Equity fundraisings: every raise (announced and unannounced) into private UK companies since 2011.
Equity fundraisings: every raise in German & Irish companies since 2024* (*actively working on making this go back to 2011)
Acquisitions: every press-announced deal across UK, Germany and Ireland, with unannounced deals backfilled to 2011 as well.
Charges & mortgages: full history back to 2001.