In 1912 the MPs of the Irish Parliamentary Party persuaded the British Parliament to pass the Home Rule Bill, granting Ireland limited self-rule with the prospect of progressive independence in the same manner as Canada, Australia etc This was fiercely opposed by Irish Unionists (Irish people who wished to remain British and overwhelmingly Protestant) and their allies in the Conservative party as they feared that as a minority in an independent Ireland they would be persecuted and discriminated against by Irish Nationalists (Irish people who wished independence from Britain and overwhelmingly Catholic) who would not support Britain in wartime. Irish Unionists formed their own armed militia, the UVF (Ulster Volunteer Force) demanding that if Ireland was to be allowed to secede from the United Kingdom that the six most northeasterly and pro-unionist counties (which came to be known as Northern Ireland) should be allowed to secede from Home Rule Ireland and remain a full part of Britain. In return Irish Nationalists formed their own militia to counter the UVF, the Irish Volunteers, opposing Northern Ireland the right to secede. Civil war threatened, however the crisis was averted by the outbreak of the First World War and both factions fought for Britain in the conflict. One of the aspects of the film which was criticized was that it omitted any reference to the Home Rule Bill at all.

At Easter 1916 a thousand strong extremist faction within the Irish Volunteers staged an armed rebellion in central Dublin with German support, demanding a fully independent united Irish Republic with no links to the rest of the British Isles. This killed over 400 people but the execution of the ringleaders created a wave of sympathy for the risers and Irish Nationalists successfully campaigned to have the surviving rebels released from prison and subsequently elected them to parliament in 1918, giving their Sinn Fein party (Gaelic for 'ourselves alone') a majority within Ireland. This incensed Irish Unionists who accused Nationalists of voting for murderers and made them more determined than ever to have Northern Ireland separate from the rest of the island.

In 1919 the Irish Republicans started killing police officers, soldiers and Unionist and moderate Nationalist civilians whom they accused of supporting the security forces, dubbing them 'informers'. By early 1920 the IRA (Irish Republican Army) had killed dozens and forced the police to withdraw from their more isolated police stations, replacing them with a shadow government of 'Sinn Fein courts'. In exchange, however, the security forces had arrested hundreds of prisoners. In the spring of 1920 the British Government, under huge pressure to find a political solution, staged a mass release of IRA prisoners as a conciliatory gesture towards Irish Nationalists. This backfired disastrously with a huge increase in IRA attacks and the security forces and Unionist civilian vigilantes ('Loyalists') increasingly turning to the extrajudicial killing of the IRA and launching reprisal attacks against the lives and property of their supporters. By the summer of 1921 the violence had intensified with groups of IRA members formed into 'Flying Columns' being pursued through the countryside and martial law introduced into Munster, Ireland's southernmost province. By the summer the IRA were growing increasingly desperate, short of funds and ammunition with many of their leading members in prison (Michael Collins later stated they were 'dead beat' and 'six weeks from defeat') But this still left the British Government with the difficulty of providing Ireland Home Rule so eventually a truce was declared and republican representatives were invited to London for negotiations.

The Royal Irish Constabulary (RIC) was the oldest of all British police forces, founded by Sir Robert Peel in 1822. It was technically an armed force but by 1916 its' arms were obsolete (issued the same model revolver as Custer used at the Little Big Horn) and seldom carried, one recruit commenting that he had never touched a firearm after basic training. After the Easter Rising the RIC had to actually borrow modern weapons from London's Metropolitan Police. In the run up to Home Rule the RIC was deliberately run down and by the time of the conflict was largely a rural force described by Irish Secretary Augustine Birrell as 'elderly men preoccupied with fishing'. The negative depiction of the RIC in this film was therefore considered inaccurate and extremely biased. The British government continued to downgrade the RIC even after the IRA began their murderous campaign. The Dublin Metropolitan Police operated in Ireland's capital separately from the RIC and remained unarmed until 1920. By the time of the conflict their 10 strong G division were the only officers in Ireland dealing with counter-terrorism and were targeted for assassination (MI5, Britain's fledgling counter-intelligence service was wholly preoccupied with the threat of Soviet Communism and less than 30 strong). By 1920 hundreds of RIC officers had resigned due to intimidation and in protest at the government's releases of IRA prisoners. Jobless First World War veterans were recruited to replace them, initially clothed in a mixture of army and police uniform and nicknamed the 'Black and Tans' after a famous foxhunt. A sub-unit within the 'Black and Tans' were the Auxillaries ('Auxies'), an elite group of ex-officers distinguishable by their Tam O'Shanter headgear (a beret with a bobble in the middle) who formed a highly mobile strike force. The Black and Tans became the bogeymen of popular Irish Nationalist history and were subsequently blamed for all vigilante killings of IRA members and supporters and revenge attacks from the security forces. The regular British Army operated in a supporting role to the police. Post conflict many Black & Tans would join the Palestine Police, dealing with another divided society. Many RIC officers would join the Royal Ulster Constabulary in Northern Ireland whilst others would join the Irish Free State's new police force, the Civic Guard (later renamed the Garda). Their recruitment triggered a mutiny amongst the pro-Republicans in the force, the Irish Free State government promptly dismissing the mutineers from the service. The Dublin Metropolitan Police continued separately until 1925 when it was merged with the Garda. Many ex-British soldiers would also join the Garda and new Irish Free State Army (also known as the National Army), some men of the Irish Regiments (Royal Dublin Fusiliers, Connaught Rangers, Leinster Regiment, Royal Irish Regiment etc) simply swapping their uniforms (also sparking a mutiny amongst the pro-Republican soldiers who were also dismissed). Irishmen from the Free State would continue to serve in the British armed forces with over 100,000 joining during World War 2 alone.

The Anglo-Irish Treaty essentially gave a slightly enhanced form of Home Rule for Southern Ireland allowing it concessions such as its' own armed forces and financial independence (although this would actually mean what would become known as the Irish Free State would be substantially poorer than the rest of the British Isles). In return Northern Ireland was granted de facto permanent partition and would remain part of Britain (Collins would break his word and continue to supply arms to the IRA in Northern Ireland). It was eventually signed by the Sinn Fein delegates after the British Prime Minister, David Lloyd George threatened an immediate return to war, Michael Collins describing the IRA's chances if the conflict resumed as akin to rabbits emerging from their warrens into the sights of the hunter's guns. The Treaty was overwhelmingly endorsed by the vast majority of the Irish population in a referendum but split the IRA, the pro-Treaty IRA arguing it was the best deal available whilst the anti-Treaty countering it was no more than the Irish Parliamentary Party could have gained peacefully if they had accepted partition. Civil War eventually broke out between the 2 factions triggered by the murder of Irish Unionist MP Sir Henry Wilson, the British government demanding Collins crush the anti-Treaty rebels.

There is no evidence to suggest that it was anything other than an ordinary ambush or that De Valera was involved in any way. In the arguments surrounding the Treaty Collins had been goaded by his political enemies that he had never himself ever fired a single shot during the conflict, using others to do his killing for him. After his convoy was attacked he seized a rifle and exposed himself to fire on the fleeing enemy only to be shot in the head.

With British support the Irish governments National Army easily cleared the IRA from their territory, forcing them to return to guerilla tactics. The Civil War was marked by even more brutality than the conflict that had proceeded it, Free State Army soldiers killing IRA prisoners by tying them to a booby-trapped barricade and then exploding it, the Royal Navy sending ships to evacuate Irish Unionists after the massacre of Irish Protestants by the IRA in Cork. The Free State Army eventually put them down by executing 5 prisoners in return for every person the IRA killed.

In real life Broys actions were exposed by documents captured from Michael Collins and he was dismissed from the police (as were several other of Collins' agents). He would later become head of the Irish Free States police force the Garda and ironically would go to great lengths to recruit former members of the Royal Irish Constabulary and Dublin Metropolitan Police into the organization. In an interview at the Cannes film festival Neil Jordan defended changing history as he said it would have been impossible for the audience to maintain sympathy with Broy if he were shown to have profited from his actions. Irish Unionist leader Peter Robinson responded that this was symptomatic of the films attitude towards historical facts. The actions of Broy and others like him made Irish Unionists paranoid about IRA infiltrators and extremely reluctant to recruit Roman Catholics into the police and government departments. Broys fate in the film is based on the story of 2 leading IRA members who were killed on the night of Bloody Sunday, officially whilst attempting to escape. Republican legend has it that they were beaten and shot in reprisal for the IRAs killings but there is no definitive evidence of this, the truth known only to the guards who shot them.

Wildly inaccurate. No IRA member was killed by a British officer who used a woman as a human shield, instead one was killed whilst his pregnant wife used herself as a shield to protect him, the woman later miscarrying their unborn child. Only one British officer was able to reach his pistol and return fire causing his would be assassins to flee but not killing any of them. No armoured car sprayed the crowds at Croke Park with bullets, the police raiding party claimed afterwards they were fired on first, army search teams recovering a dozen pistols from the grounds. Bloody Sunday is depicted as an overwhelming success but in reality Collins aimed to kill 35 targets but only killed 13, only 9 of them the intended victims and only 7 of those intelligence officers. The Cairo Gang was up to 100 strong and one of its members, Robert Jeune stated that it barely affected their operations at all.

Collins was lauded by Irish Republicans as 'The Man who Beat the British', reversing their long history of defeats, famed for his energy and organizational skills. However the Home Rule Bill gave him unique advantages by making some form of independence inevitable, creating turncoats such as Broy and making Irish Unionists and moderate Nationalists reluctant to help the security forces who would not be able to protect them afterwards. The British government also continuously tried to find a political solution and repeatedly released IRA prisoners in an ill-fated attempt at appeasement. Collins was a prodigious record keeper and British Intelligence captured so many of his documents that they had to create an entire department, the 'Raid Bureau' to read them all. Sir Ormonde Winter, the head of British intelligence later stated in his memoirs that he considered Collins documents his number one source of information on the IRA.

Collins is regarded by Irish Unionists as simply a murderer and terrorist. Amongst Irish Republicans he is considered a role model but one who split the movement through compromise. Irish Nationalists have a more ambiguous attitude towards him, largely agreeing with his aims whilst disapproving of his methods.

De Valera would eventually be released from prison and elected the premier of the Irish Free State, becoming its' president when it became a republic in 1949. He would not only intern IRA members and allow them to die on hunger strike but would borrow Britain's leading hangman Albert Pierrepoint to execute them. In 1937 he would introduce a new constitution giving the Roman Catholic church a special position within the country and would keep the Irish Free State neutral during World War 2, leaving Britain to rely on Northern Ireland to help win the Battle of the Atlantic.

No, only one, Thomas Clarke, was stripped by Inspector Swazny of the RIC. Swazny was not only angered by the hundreds of deaths in the rising but that Clarke had previously been sentenced to death for a bombing campaign which had killed several people but had been spared and released to open a tobacconists, many of whose customers were British soldiers. Swazny was later murdered as he came out of church on Collins' orders, his death prompting revenge attacks by Loyalists against those they suspected of supporting the IRA which rapidly descended into full scale sectarian rioting and tit-for-tat killings.

Between the Easter Rising in 1916 and the end of the Civl War in 1923 the death toll is reckoned to be nearly 3500 in a population of roughly 4 million (as opposed to over 30,000 Irishmen killed in the Great War and an equivalent number dying in the Spanish flu epidemic afterwards). Between 1919-1921 the IRA would kill over a thousand people whilst the security forces would kill 500 in return (but take nearly 5000 prisoners, some of whom were repeatedly captured and released). The civil war which followed killed roughly 2000.