Tributes have been paid to a leading expert on historic Welsh buildings, who has died along with his teenage son in a scuba diving accident near Malta.
Richard Avent, 58, from Raglan in Monmouthshire, and 16-year-old Rhydian, both drowned during a family holiday on the island of Gozo.
Mr Avent was a chief inspector with Cadw, the assembly government's historic environment service.
First Minister Rhodri Morgan said he was shocked and saddened at the deaths.
Cadw said the deaths had brought "deep sadness" to Mr Avent's colleagues.
A statement read: "Richard's achievements over the past 30 years in developing the understanding, management and promotion of the historic environment of Wales have been enormous.
"He was instrumental in establishing the four Welsh Archaeological Trusts, and with his support the local archaeological service which they provide has flourished to become the envy of the other home nations.
"He has been the champion of Welsh castles and their builders, and has an international reputation amongst castle experts.
"He pioneered the study of historic landscapes in Wales and, through the Register of Historic Landscapes, has ensured their future in the face of ill-considered change."
Mr Avent graduated from the University of Wales, Cardiff and worked briefly at Carmarthen Museum.
In 1973 he joined the Ancient Monuments Branch of the Department of the Environment as Assistant Inspector of Ancient Monuments in Wales and was promoted to Inspector in 1976.
In 1984 he was appointed the Principal Inspector of Ancient Monuments and Historic Buildings soon after the formation of Cadw, and in 1990 he became Chief Inspector.
Mr Avent was the president of the Cambrian Archaeological Association, a founder member of the ICOMOS (UK) World Heritage Committee, and served on the committees of the Society of Antiquaries of London, the Castle Studies Group and Ch‚teau Gaillard.
He was the author of Cadw's guidebooks to Laugharne, Criccieth, Dolwyddelan, Dolbadarn and Ewloe Castles, and Castell y Bere.
He wrote the book, Cestyll Tywysogion Gwynedd - Castles of the Welsh Princes (1983), and co-edited Castles in Wales and the Marches (1987).
He published his research into Anglo-Saxon brooches in two volumes in 1975, and contributed many articles to local, national and international archaeological journals.
Rhodri Morgan said: "As Chief Inspector of CADW, the Welsh Assembly Government's historic environment service, Richard Avent made a massive contribution to the protection and conservation of Wales' most treasured historic sites and buildings.
"His achievements over the past 30 years in the field of archaeology and the historic environment were enormous and he earned an international reputation for his expertise as a champion of Welsh castles.
"Laugharne Castle, a site he loved and where he excavated and conserved the ruins throughout his whole career, now stands as testament to his passion and devotion to Wales' historic environment.
"That was where he helped create one of the most beautiful places in Wales."