Complex sentence: His troops advanced and made their way through different valleys and by every approach that they could discover got nearer to them and the Afghans after standing only for an instant took to flight without even shooting an arrow.
Split into simpler sentences: His troops advanced and made their way through different valleys and by every approach that they could discover. They got nearer to them, and the Afghans after standing only for an instant took to flight without even shooting an arrow.