Academics from the North, Britain and the Republic have received major awards for outstanding scholarship from the Royal Irish Academy.
The Cunningham Medals were presented last night at a ceremony at the academy's headquarters in Dublin. They were given to world-class researchers in the fields of physics, architectural history, engineering and history.
The recipients were described as "inspirational figures whose startling achievements have enhanced the world of learning and Ireland's standing in that world" by the academy's president, Prof David Spearman.
Physicist Prof Daniel Bradley received a medal in recognition of his ground-breaking work in pulsed laser technology. Born in Co Derry, he was to the fore in the development of opto-electronics.
Dr Maurice Craig won a medal for his work in architectural history. He is the author of a seminal work on Dublin's historical and social development and he was born in Belfast.
Sir Bernard Crossland won a Cunningham for his distinguished research career in engineering. Born in England, he is an expert in metal fatigue and explosion welding and friction welding.
The fourth medal went to Prof David Beers Quinn, an historian with an international reputation for his pioneering work on the 16th century colonisation of the Americas. Born in Dublin, he established links between Tudor settlements in Ireland and the Americas.
The Cunningham medal is presented once every three years and is the academy's most prestigious award for research achievement. The first was awarded in 1796. It is named after Timothy Cunningham, a barrister who bequeathed £1,000 to the academy to help further its aims in promoting the study of the sciences, humanities and social sciences.