Complex sentence: Amnestied by the emperor of Austria in 1866, he returned home and reentered public life; was from 1867-1876, and again in 1884, a member of the newly reformed Diet of Hungary, joining the Deák party.
Split into simpler sentences: Amnestied by the emperor of Austria in 1866, he returned home and re-entered public life. He was in 1867--76 and again in 1884 a member of the newly reformed Diet of Hungary, where he joined the Deák party.