The Government of the Han Dynasty in ancient China had its capital at Chang'an, and later Luoyang. The emperor headed the government, promulgating all written laws, serving as commander-in-chief of the armed forces, and presiding as the chief executive official. He appointed all government officials who earned a salary of 600 bushels of grain or more with the help of advisors who reviewed each nominee. Near the beginning of the dynasty, semi-autonomous regional kings rivaled the emperor's authority. This autonomy was greatly diminished when the imperial court enacted reforms following the threats to central control like the Rebellion of the Seven States. The empress dowager could either be the emperor's actual or symbolic mother, and was in practice more powerful than the emperor, as she could override his decisions. The emperor's executive powers could also be practiced by any official upon whom he bestowed the Staff of Authority. These powers included the right to execute criminals without the imperial court's permission. The highest officials in the central bureaucracy, who provided advisory, censorial, executive, and judicial roles in governing the empire, consisted of cabinet members known as the Excellencies, heads of large specialized ministries known as the Nine Ministers, and various metropolitan officials of the capital region. Local government divisions, in descending order by size, were the province, commandery, county, and district.