Complex sentence: The future taoiseach Seán Lemass was the managing editor of the Irish press who spearheaded the launch of the sunday paper, with the first editor Colonel Matt Feehan, many of the Irish Press journalists contributed to the paper.
Split into simpler sentences: The future Taoiseach Seán Lemass was the managing editor of the Irish press who spearheaded the launch of the Sunday paper, with the first editor Colonel Matt Feehan. Many of the Irish Press journalists contributed to the paper.