Complex sentence: Renner was always interested in politics and became librarian in parliament and member of the Austrian Social Democratic Party (SPÖ) in 1896 and he started to represent the party in the Reichsrat in 1907.
Split into simpler sentences: Renner was always interested in politics and became librarian in parliament and member of the Austrian Social Democratic Party (SPÖ) in 1896. He started to represent the party in the Reichsrat in 1907.