Special thanks to the following individuals and institutions that have contributed to this project:
Amgueddfa Cymru – Museum Wales
Bank of England & Bank of England Museum
Birmingham Museums Trust
Bonhams auction house
British Newspaper Archive
CADW
Christie’s auction house
Chrysler Museum of Art
Collections of the Grand Palais and the Louvre
Compton Verney Art Gallery and Park
Damian Maruscha-Owen
Dave Morris & the Morris Family
Factum Foundation
Fondazione Giorgio Cini
Gareth Elms
Getty Provenance Index
Gareth Hughes
Glamorgan Archives
Greenhatch Group
Harlaxton College & Harlaxton Manor
Iwan Williams
Jeffrey-Lewis Jones
John Vivian Hughes
Lacy Scott & Knight auction house
Liechtenstein Museum & Palais Schwarzenberg
Llyfrgell Genedlaethol Cymru / The National Library of Wales
Megan Kelleher
Merthyr Mawr Estate
Museum Prinsenhof Delft
National Gallery of Ireland
National Trust Collections
National Trust: Dinefwr Park & Newton House
National Trust: Lacock
National Trust: Penrhyn Castle & Garden
Penllergaer Estates & The Llewelyn Family
Penrice Estate & Thomas Methuen-Campbell
Pinacoteca di Brera
Port Talbot Historical Society
Richard Burton Archives
Royal Collection Trust
Royal Commission on the Ancient and Historical Monuments of Wales (RCAHMW)
SCALA Archives
Sotheby’s auction house
Stowell Park Estate
The British Museum
The Friends of Margam Park
The Leiden Collection, New York
The National Gallery
Towneley Hall Art Gallery and Museum
Victoria and Albert Museum
West Glamorgan Archive Service