Complex sentence: England had been aiming for sovereignty over Scotland since the 14th century wars of independence, and the ensuing 300 years brought many volatile events that directly affected the lives of every border family, from tenant farmer to landlord to border official.
Split into simpler sentences: England had been aiming for sovereignty over Scotland since the 14th century wars of independence. Many volatile events directly affected the lives of every border family, from tenant farmer to landlord to border official.