Complex sentence: As Socrates marched across the countryside of Bithynia, he eventually approached the capital, Nicomedia, wher Nicomedes IV barricaded himself inside his castle.
Split into simpler sentences: As Socrates marched across the countryside of Bithynia, he eventually approached the capital of Bithynia, Nicomedia. As he approached the capital, Nicomedes IV barricaded himself inside of his castle.