Tuscany participated in the Wars of Castro, the last time Medicean Tuscany was involved in a military conflict and inflicted a defeat on the forces of Pope Urban VIII in 1643. The treasury was so empty that when the Castro mercenaries were paid for the state could no longer afford to pay interest on government bonds. The interest rate was lowered by 0.75%. The economy became so decrepit that barter trade became prevalent in rural market places.