Complex sentence: Two men wearing Courtenay livery attacked Sir Philip Chetwynd, a friend of Bonville, on the road to London, apparent evidence that the Council's arbitration of November 1440 had failed.
Split into simpler sentences: Two men wearing Courtenay livery attacked Sir Philip Chetwynd, a friend of Bonville, on the road to London. Apparent evidence that the Council's arbitration of November 1440 had failed.