The Dutch tried one strategy after another over the course of four decades. An expedition under Major General Johan Harmen Rudolf Köhler in 1873 occupied most of the coastal areas. Köhler's strategy was to attack and take the Sultan's palace. It failed. The Dutch then tried a naval blockade, reconciliation, concentration within a line of forts, and lastly passive containment. They had scant success. Reaching 15 to 20 million guilders a year, the heavy spending for failed strategies nearly bankrupted the colonial government.