Complex sentence: During the Peninsular War the area of Costa del Sol was considered of secondary importance and it was seized by the French forces with little opposition and until 1810 the partisan activity in the region was close to none.
Split into simpler sentences: During the Peninsular War the area of Costa del Sol was considered of secondary importance. It was seized by the French forces with little opposition and until 1810 the partisan activity in the region was close to none.