Summer excavations at an island dubbed the “Egypt of the North” have revealed the deliberate demolition of a Pictish-era roundhouse and settlement and a takeover by Viking arrivals.Around 18 archaeologists have spent three months at Swandro Bay on the Orkney island of Rousay this summer with the team making an apparent breakthrough in the timeline of the site where a giant broch-style roundhouse, likely inhabited by an island elite, towered over surrounding homes and workshops.

It comes as archaeologists work against erosion of the site due to rising tides and the impact of global warming, with half the roundhouse now having slipped into the sea and seawater encroaching on the remains.