Complex sentence: It was created by a group of journalists and activists of the underground democratic opposition press From the onset, the newspaper's Editor-in-Chief has been Adam Michnik, an intellectual and prominent member of democratic opposition in the 60-80's.
Split into simpler sentences: It was created by a group of journalists and activists of the underground democratic opposition press. Since the beginning, the newspaper's Editor-in-Chief has been Adam Michnik, an intellectual and prominent member of democratic opposition in the 60-80's.