Complex sentence: Frank Aiken (13 February 1898--18 May 1983) was a commander of the Irish Republican Army and an Irish Sinn Féin politician and a founding member of Fianna Fáil.
Split into simpler sentences: Frank Aiken (13 February 1898--18 May 1983) was a commander of the Irish Republican Army and an Irish politician. Orginally a member of Sinn Féin, he was later a founding member of Fianna Fáil.