On February 3, 1919, Eamon De Valera, Sean McGarry and Sean Milroy escaped from Lincoln Prison with a key smuggled in a cake and stole through the night with Michael Collins.

Eamon De Valera escaped from Lincoln Prison in Lincolnshire in 1919 and returned 31 years later in 1950, between his first and second terms as Taoiseach (Prime Minister) of Ireland.

How did this extraordinary prison break happen? Just your typical baking and locksmithery scheme.

De Valera, McGarry, and Milroy were imprisoned for allegedly plotting against the British with Germany - charges that were later proved to be unfounded.

Read More: John F. Kennedy branded de Valera "a lunatic" after 1945 visit to Ireland

Eager to continue the campaign for Irish independence, the three Irishmen wanted out. So Michael Collins, who was head of IRA intelligence at the time, hatched a plan to get them out.

There were a number of false starts on the journey to their freedom. De Valera managed to make a copy of the prison chaplin’s key using candle wax and send it to the outside. However, it took three tries for Dev’s comrades on the outside to make a suitable copy - the first two, also smuggled into Lincoln Prison inside of cakes, did not work.

A functional key in hand, on February 3, 1919, at approximately 7:40 pm, Dev, McGarry, and Milroy calmly unlocked the doors to their cells, locked them behind them, and walked out into the prison’s exercise yard to meet Collins, Harry Boland, and Frank Kelly.

They stole through the back gardens of Lincolnshire in the dark, stopped at the Adam and Eve Pub, and caught a taxi, and made their way to a safe house in Manchester.

The prison guards reportedly noticed the three were missing by 9:30 pm that same night, but were baffled as to how the doors to their cells were locked.

Later that same year, de Valera was able to make a trip to America - and even became an honorary Native American chief

Thirty-one years later, after the Irish War of Independence, after the Irish Civil War, and after serving his first term as Taoiseach, de Valera returned to Lincoln Prison for a visit.

Read More: Remembering Eamon de Valera, a voice in Irish politics for over 50 years 

Lincolnshire Live recently shared quotes from an article that ran in the Lincolnshire Echo to mark the occasion:

"A few minutes after nine o’clock, Eamon de Valera rang the bell at the main gate of Lincoln Prison.

"The door opened and a few seconds later, in stepped the man who had left unnoticed by the back door more than 31 years ago.

"With Fenner Brockway, Labour MP for Eton and Slough, who was serving a term of solitary confinement in the gaol at the time of 'Dev’s' escape, he was paying a courtesy call to the prison and in the course of a 35-minute tour he visited his old cell – D29.

"On a board describing the present occupant was the word 'escapee'.

"They were accompanied on their trip around the prison by the Governor, Brigadier E J Paton-Walsh and the chief warder.

"The visit was made with the permission of the Prison Commissioners.

"Mr Brockway told the Echo: 'Eamon de Valera reconstructed his escape for the benefit of the Governor.'

"And Mr de Valera added: 'I explained in great detail how we got out.'

"'Dev' asked the Governor if he could see the present master key and learned that since his escape the locks and, of course, the keys had been changed."