Complex sentence: Lüderitz began its life as a trading post, fishing, and guano-harvesting town, but when diamonds were discovered in 1909 in nearby Kolmanskop, Lüderitz enjoyed a sudden surge of prosperity.
Split into simpler sentences: Lüderitz began its life as a trading post, with other activities in fishing and guano-harvesting. In 1909, after the discovery of diamonds nearby, Lüderitz enjoyed a sudden surge of prosperity.