Complex sentence: After leaving school he went up to King's College, Cambridge, where his socialist views earned him three defeats for the Secretaryship of the Cambridge Union (the only office generally then contested) and then the London School of Economics and the Middle Temple.
Split into simpler sentences: After leaving school he went up to King's College, Cambridge. After three attempts at the Secretaryship of the Cambridge Union (the only office generally then contested) he went on to the London School of Economics and the Middle Temple.