Complex sentence: Cooper attended Bishop Wordsworth's School in Salisbury, whose alumni include the actor Ralph Fiennes who also worked in his brother-in-law's ice cream shop, and then went on to study politics, philosophy and economics at Trinity College, Oxford University.
Split into simpler sentences: Cooper attended Bishop Wordsworth's School in Salisbury, whose alumni include the actor Ralph Fiennes whom also had worked in his brother-in-law's ice cream shop. After graduating from Wordsworth's Cooper went on to study politics, philosophy and economics at Trinity College, Oxford University.