Question: The father of Vivion de Valera led the introduction of what document?
Context: External association was a hypothetical relationship between Ireland and the British Commonwealth proposed by Éamon de Valera in 1921–22, whereby Ireland would be a sovereign state associated with, but not a member of, the Commonwealth; the British monarch would be head of the association, but not head of state of Ireland.  De Valera proposed external association as a compromise between isolationist Irish republicanism on the one hand and Dominion status on the other.  Whereas a full republic could not be a member of the Commonwealth until the London Declaration of 1949, a Dominion could not be fully independent until the Statute of Westminster 1931. The Irish presidential election of 1966 was the fifth presidential election in Ireland and was held on 1 June 1966.  Outgoing president Éamon de Valera, 83 and with a rapidly deteriorating eyesight, reluctantly agreed under pressure from his Fianna Fáil party to seek a second term.  Fine Gael decided to run one of its younger TDs, Tom O'Higgins, against him.  In an astonishing upset, O'Higgins came within 1% (or 10,718 votes) of defeating de Valera, who had been the predominant force of the republic since 1932 and led the government for decades until his ascent to the presidency in 1959.  De Valera left the blame for this near-defeat with his campaign manager Charles Haughey. De Valera's Cottage is a cottage and National Monument located in County Limerick, Ireland.  It was the childhood home of Irish rebel leader, and later President of Dáil Éireann, President of the Executive Council of the Irish Free State, Taoiseach and President of Ireland, Éamon de Valera (1882–1975). Vivion de Valera (13 December 1910 – 16 February 1982) was an Irish scientist, businessman, lawyer and politician.  He was the eldest child of Éamon de Valera and Sinéad de Valera and was named after his paternal grandfather, Juan Vivion de Valera. Éamon de Valera ( ; ] ; first registered as George de Valero; changed some time before 1901 to Edward de Valera; 14 October 1882 – 29 August 1975) was a prominent politician and statesman in 20th-century Ireland.  His political career spanned over half a century, from 1917 to 1973; he served several terms as head of government and head of state.  He also led the introduction of the Constitution of Ireland. "On Language & the Irish Nation", was the title of a radio address made by Éamon de Valera, then Taoiseach of Ireland, on Raidió Éireann on St. Patrick's Day (17 March) 1943.  It is often called The Ireland that we dreamed of, a phrase which is used within it, or the "comely maidens"' speech, a misquotation.  The speech marked the 50th anniversary of the foundation of the Gaelic League ("Conradh na Gaeilge"), a group promoting Irish culture and the Irish language.  In the most frequently quoted passage of the speech, de Valera set out his vision of an ideal Ireland: Rúaidhrí de Valera (1916–1978) was an Irish archaeologist most known for his work on the megalithic tombs of his country.  He was the son of Éamon de Valera. The policy of Irish neutrality during World War II was adopted by the Oireachtas at the instigation of the Taoiseach Éamon de Valera upon the outbreak of World War II in Europe.  It was maintained throughout the conflict, in spite of several German air raids by aircraft that missed their intended British targets and attacks on Ireland's shipping fleet by Allies and Axis alike.  De Valera refrained from joining either the Allies or Axis powers.  While the possibility of not only a German but also a British invasion were discussed in the Dáil, and either eventuality was prepared for, with the most detailed preparations being done in tandem with the Allies under Plan W, De Valera's ruling party, Fianna Fáil, supported his neutral policy for the duration of the war. Patrick Moylett (1878–1973) was a 20th-century Irish nationalist who, during the initial armistice negotiations to end the Irish War of Independence, briefly served as president of the Irish Republican Brotherhood during late-1920.  A successful businessman in County Mayo and County Galway, he was a close associate of Arthur Griffith and frequently traveled to London acting as a middleman between Sinn Féin and officials in the British government.  He ran a business that was used as a front to import armaments for the cause and held that many of those that became closest associates of Éamon de Valera during the civil war rift had at one time worked for the British.  Particularly that Erskine Childers despite his involvement with the Asgard (yacht) and his close association with Éamon de Valera had been in the direct pay of the Admiralty Naval Intelligence Service up till 1916 before becoming secretary to the Éamon de Valera led treaty discussions. Comhairle na dTeachtaí was an Irish republican parliament established by opponents of the 1921 Anglo-Irish Treaty and the resulting Irish Free State, and viewed by republican legitimatists as a successor to the Second Dáil.  Members were abstentionist from the Third Dáil established by the pro-Treaty faction.  Just as the First Dáil established a parallel Irish Republic in opposition to the British Dublin Castle administration, so Comhairle na dTeachtaí attempted to establish a legitimatist government in opposition to the Provisional Government and Government of the Irish Free State established by the Third Dáil.  This legitimatist government, called the Council of State, had Éamon de Valera as President.  In 1926 de Valera resigned as President, left the Sinn Féin party and founded Fianna Fáil, which in 1927 entered the Fourth Dáil.  Comhairle na dTeachtaí, never more than a symbolic body, was thereby rendered defunct.  In 1930 Cumann na nGaedheal TDs alleged in the Dáil that de Valera had addressed Comhairle na dTeachtaí in December 1926, after the foundation of Fianna Fáil; this was to cast aspersions on de Valera's commitment to the Constitution of the Irish Free State.
Answer: Constitution of Ireland