Complex sentence: Barrow Raiders are the oldest side in what is now Cumbria and are based in what was part of Lancashire but other Cumbrian sides exist and have existed in the traditional county of Cumberland, namely Whitehaven, Workington Town and at one time Carlisle.
Split into simpler sentences: Barrow Raiders are the oldest side in what is now Cumbria and are based in what was part of Lancashire. Other Cumbrian sides exist and have existed in the traditional county of Cumberland, namely Whitehaven, Workington Town and at one time Carlisle.