According to economic historian Jan De Vries, Venice's economic power in the Mediterranean had declined significantly by the start of the 17th century. De Vries attributes this decline to the loss of the spice trade, a declining uncompetitive textile industry, competition in book publishing due to a rejuvenated Catholic Church, the adverse impact of the Thirty Years' War on Venice's key trade partners, and the increasing cost of cotton and silk imports to Venice. In addition, Portuguese sailors had rounded Africa, opening another trading route to the east.