The Head of State of Mexico is the person who controls the executive power in the country. Under the current constitution, this responsibility lies with the President of the United Mexican States, who is head of the supreme executive power of the Mexican Union. Throughout its history, Mexico has had several forms of government. Under the federal constitutions, the title of President was the same as the current one. Under the Seven Laws (centralist), the chief executive was named "President of the Republic". In addition, there have been two periods of monarchical rule, during which the executive was controlled by the Emperor of Mexico.