It has long been held that the Seleucid court hierarchy was created by the dynasty's weak second-century rulers. This article claims that, on the contrary, it was instituted earlier by their stronger predecessors when they faced a pressing need to organize newly conquered territories. They drew in part upon models from elsewhere (Achaemenid and Ptolemaic, especially). As a result, the Seleucid regime acquired long-term robustness, even though its functioning still remained dangerously dependent upon the king himself.