Prior to the sixteenth century, the political and economic system that spanned the distance from China to Europe was constructed of a series of loosely connected and largely autonomous subsystems. Communication—except for commerce—was intermittent, but subordinate systems such as Southeast Asia borrowed extensively from the East Asian, South Asian, and Middle Eastern subsystems. For example, Ottoman links to the Islamic kingdoms of Southeast Asia, although important, were largely restricted to religious exchanges and occasional advice on matters of state. Southeast Asia had great latitude for autonomous action, and it drew strength from China, India, and other subsystems for its own systemic development.