Situated on the most westerly point of County Mayo, in neutral Ireland, a message from the Blacksod Lighthouse during 1944 helped change the course of the war as Robin J Brooks explains.
D–DAY

RAF Meteorological Officer, Gp Capt James Stagg, D-Day weather forecaster.
Standing 13 metres above sea level, the Blacksod Lighthouse is over 151 years old. Carved from the rocks beneath where it stands, its flashing light has given mariners safe entry to a treacherous harbour for decades. It has also served as a weather reporting station passing vital weather information directly to the Irish Meteorological Service, now known as the Met Eireann, but in 1944 it flashed some of its most important signals.