Complex sentence: Before the seventeenth century, with difficult terrain, poor roads and methods of transport there was little trade between different areas of Scotland and most settlements depended for subsistence on what was produced locally, often with very little in reserve in bad years.
Split into simpler sentences: Before the seventeenth century, with difficult terrain, poor roads and methods of transport there was little trade between different areas of Scotland. Most settlements depended for subsistence on what was produced locally, often with very little in reserve in bad years.