Yesterday was the seventy-fifth anniversary of the opening sequence of Saving Private Ryan, when thousands of American soldiers in search of continental Europe, led by Matt Damon,  came ashore at Curracloe Beach in Co. Wexford by mistake. While they were, technically, in Europe, they were nowhere near their intended target, the coast of Normandy and there were no Germans around.

Or something like that anyway!

Actually, it was the diamond anniversary of D-Day, or Operation Overlord, the long-awaited Allied invasion of Europe when more than 150,000 American and British troops came ashore at five Normandy beaches. Which makes it sound a bit like a day trip across the English channel. Ten thousand Allied casualties attest otherwise.

The entire operation was planned and executed by a group of Bigots. This is not to suggest that the spiritual ancestors of Stephen Yaxley-Lennon and Marine Le Pen dreamed up the Normandy invasion. Back in 1944 military and intelligence personnel who had the requisite security clearance for Operation Overlord were on what was called a BIGOT list and were thus known as ‘bigots’. The name would certainly have put off any German spies, who might even have had legitimate hopes of recruiting someone they heard being so described.

The origin of the phrase is far too complicated and shrouded in mystery to deal with here. Suffice it to say that it is the words ‘To Gib’ reversed, the ‘Gib’ in question being Gibraltar. Happy now? No, I didn’t think so.

Today is the seventy-fifth anniversary of D-Day +1, by which time the five beachheads had been established and thousands of British and American troops were coming ashore. It could have been otherwise. The harrowing opening sequence of Steven Spielberg’s Saving Private Ryan depicts the amphibious landing at the beach code-named Omaha. Determined German defence meant that Omaha Beach accounted for around half of the Allied casualties.

But is it the case that things could have been very different were it not for a humble Irish weather station in Co. Mayo. The Bigots could plan all they liked, they could train, they could prepare, they could cover as many contingencies as possible, but the one element over which they had no control was the weather. Conditions in May 1944 had been excellent but then turned nasty. 5 June had been the intended date for the invasion but adverse weather conditions resulted in a twenty-four-hour postponement. The skies the following day didn’t look much better and a further deferral would not just have been for twenty-four hours but closer to two weeks. The phase of the moon, and the prevailing tides needed to be right as well.

And that was when a humble Irish lighthouse keeper named Ted Sweeney did his bit to change world history. Although Ireland was neutral it still supplied vital weather reports to the UK. The lighthouse on Blacksod Bay, manned by Sweeney, had a bird’s eye view of conditions on the Irish west coast. Sweeney’s report, of diving barometric readings and a force six wind on 3 June, had been instrumental in the postponement of the invasion.  Twice that day Ted’s daughter Maureen, who worked in the local post office, took calls from London from a woman with a cut-glass English accent. She wanted to talk to Ted Sweeney. Twice she asked him to confirm the readings he had made. Probably getting a little impatient second time around, he duly did as he was asked. He had no idea that he was hitting the pause button on the invasion of Europe

But at noon the following day, 4 June Ted Sweeney, filed the report that General Dwight D. Eisenhower had been waiting for. The heavy rain of the previous day had passed, cloud cover was at 900ft, and visibility was clear. This brief respite from stormy conditions would reach the English channel in time to allow Operation Overlord to proceed.

All of which was just as well. Because the weather in July was just as bad. Were it not for Ted Sweeney we might well be commemorating D-Day in August.

Although Ireland was a neutral country some Irishmen did play a role in Operation Overlord. The Royal Ulster Rifles, which included many volunteer soldiers from the Irish Free State, had two battalions involved in D-Day. But it may well have been non-combatant Ted Sweeney who played the crucial Irish role.

So, in answer to the question, did a neutral Irish weather station make a huge contribution to the success of D-Day seventy-five years ago this week? Yes, it did, it’s NOT fake history.