The Peninsular war proved a major disaster for France. Napoleon did well when he was in direct charge, but severe losses followed his departure, as he severely underestimated how much manpower would be needed. The effort in Spain was a drain on money, manpower and prestige. Historian David Gates called it the "Spanish ulcer." Napoleon realised it had been a disaster for his cause, writing later, "That unfortunate war destroyed me ... All the circumstances of my disasters are bound up in that fatal knot."