Iran's complex and unusual political system combines elements of a modern Islamic theocracy with democracy. A network of unelected institutions controlled by the highly powerful conservative Supreme Leader is countered by a president and parliament elected by the people.
For much of the last decade, Iranian politics has been characterised by continued wrangling between these elected and unelected institutions as a reformist president - and, at times, parliament - struggled against the conservative establishment.
But with hardliners' regaining control of the parliament in 2004 and the presidency in 2005, all the organs of government are now dominated by conservatives.
The BBC News Website looks at how Iran's political system works and who wields the power.