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Jack Lynch served as Taoiseach, or Prime Minister, of Ireland before Liam Cosgrave. Lynch held the position from 1966 to 1973, leading the Fianna Fáil party. During his tenure, he oversaw significant economic and social reforms, including the introduction of free secondary education and the establishment of the Irish Land Commission. Lynch's successor, Liam Cosgrave, took office in 1973 as the leader of the Fine Gael party.