Hitler's plan to invade Northern Ireland in the Second World War
The document contains detailed maps and postcards of the country and has been kept by a family out of public view since the end of war.
And it reveals that even though Ireland was officially neutral during the conflict, Hitler still viewed the country as a target for invasion.
The Irish allowed German U-boats and submarines into their waters during the Second World War, but the booklet entitled Militargeographische Angaben uber Irland pinpoints key cities and other sites in Ireland for destruction.
A new document has come to light which reveals Hitler's plans to attack Ireland, left. The dossier includes eight pull out maps where key cities and other important locations are numbered, right.
It is accepted that the plan was poorly constructed, and not treated with any seriousness by the Abwehr, or German Foreign Ministry although at this stage they did not recognise the IRA as "hopelessly immature". In so much as the plan was considered, it was considered a measure of IRA intent — willingness to assist. It is not known whether any serious planning was done around Kathleen, although the plan appears to have been widened in scope, maybe by Görtz, or perhaps Kurt Student, who presented a similar plan to Hitler in January 1941, to include parachute drops of German troops around Divis Mountain and Lisburn in combination with the amphibious assault on Lough Swilly and Magilligan Point
In September 1939, the UK went to war with Germany when it invaded Poland ignoring British and French demands for it not to. Northern Ireland, as part of the UK, found itself at war too. Eire, being a small country with few military resources, immediately declared neutrality.
The only things to mar the good relations between the two states were (a) de Valera condemning the siting of US bases in Northern Ireland (b) de Valera expressing his condolences to the German ambassador when Hitler died (c) Britain's public, verbal, attack on Eire when the war was over for not joining the 'crusade against fascism'
The scarce copy of 'Militargeographische Angaben uber Irland' published in 1940 has been uncovered for the first time after it was kept in the same family following the end of the Second World War
On September 17, 1940, Hitler was forced to scrap plans to invade Ireland - called Operation Sealion - because of the Luftwaffe's failure to gain air supremacy over England during the Battle of Britain
Although the Nazi offensive never took place, experts believe the book reveals what could have happened if the Hitler had conquered Britain
The document is expected to fetch up to £600 when it goes under the hammer at Ludlow Race Course tomorrow
Among the postcard set is this image of Stormont, in Belfast, which is now the home to the Northern Ireland Assembly
This grainy image shows the docks area of Belfast which would have been a key port for Hitler to seize to launch any attack on the country
Although historians have discovered invasion plans for Britain before this is the first time a detailed plan for taking Ireland has been uncovered
Expert Richard Westwood Brookes said the document shows how the Irish were wrong to believe they were safe from invasion after accommodating the Nazis during the war
This picture shows the built up centre of Belfast - experts are expecting interest from Irish collectors as the dossier provides a chilling reminder of what might have been had Hitler followed through with plans to invade the country
It made military sense for the Germans to invade Ireland as it was a perfect location to set up for an invasion of England
The 2,464ft Mount Errigal situated near Gweedore in County Donegal
The quiet spot of Glenalough, a glacial valley in County Wicklow, was also highlighted in the document
The contents page for the document highlights the detailed extent to which the Nazis had planned an invasion of Ireland
This second part covers a period of World War II called Operation Plan Green – Hitler’s plan to use Ireland as a back door into into the UK. The Irish Prime Minister, Eamon de Valera, had decided that keeping Ireland out of World War Two was the best policy despite numerous calls from the Allies for Ireland to enter the war. He had almost entire support in parliament (just one member of parliament voted in favor of joining the war) and the overwhelming support of the population that saw entering the war as “helping the old enemy (UK)”.
Also, despite promises of weapons and tanks, Ireland’s military was mostly infantry based, and it would have taken considerable investment to achieve a fighting standard at the time. Nevertheless, Ireland, the most western of European countries, was of keen strategic importance to both sides of the war. The Allies wanted to use Irish ports and airfields to patrol the Atlantic, and Hitler formulated ‘Plan Green’, which was a plan to invade Ireland as a ‘backdoor’ into the UK.
Ireland had strategic links to America so it would have made tactical sense for the Nazis to occupy the country swiftly
The front page of the dossier which shows that no one was off limits for the Nazis when it came to Hitler
Key spots were plotted on a series of eight fold-out maps, which would have been used during 'Operation Sealion'