He led the Irish delegation at the negotiations that produced the 1921 Anglo-Irish Treaty, and served as President of Dáil Éireann from January 1922 until his death in August 1922.
After a short spell in South Africa, Griffith founded and edited the Irish nationalist newspaper The United Irishman in 1899.
In September 1921, he was appointed chairman of the Irish delegation to negotiate a treaty with the British government.
After months of negotiations, he and the other four delegates signed the Anglo-Irish Treaty, which created the Irish Free State, but not as a republic.
This led to a split in the Dáil.
After the Treaty was narrowly approved by the Dáil, de Valera resigned as president and Griffith was elected in his place.
The split led to the Irish Civil War.
Griffith died suddenly in August 1922, two months after the outbreak of that war.