[1] The trust maintained Historic Environment Records for their area to provide archaeological advice to central government, planning authorities and other public bodies.

In the 1970s Wales was the first part of the UK to develop a fully national system of what were then called ‘Sites and Monuments Records’; this fully computerised system was pioneered by Don Benson who was then Chief Executive of the Dyfed Archaeological Trust.

[3] The Welsh Government is required to maintain HERs as a statutory obligation under the Historic Environment (Wales) Act 2016; these active databases are an essential component of the planning system in Wales.

In September 2023 the four Welsh Archaeological Trusts agreed to merge.

The resulting organisation has a pan-Wales overview, whilst maintaining regionally-based operations.