Complex sentence: In 1893 he founded the Gaelic League, along with Douglas Hyde, and was unpaid secretary from 1893-1897 and then became the initial editor of the League's official newspaper "An Claideamh Soluis" (1899--1901).
Split into simpler sentences: In 1893 he founded the Gaelic League, along with Douglas Hyde, and was unpaid secretary from 1893-1897. He then became the initial editor of the League's official newspaper "An Claideamh Soluis" (1899--1901).