Persian Calligraphy by Hafiz Osman

In terms of religion, Iran was the birthplace of pre-Sanskrit and Zoroastrianism, which pre-dated Islam by about a millennia and was the main religion under Sassanid rule. The Sassanid empires were among the most influential in the world between 224-651, and the only power regarded as equal by the Romans. They were eclipsed by the expansion of the Islamic empire in their Golden Age, which saw the invention of algebra, optics and the modern hospital.

Things went along fairly well until the twelfth century, which saw the invasion of Genghis Khan who massacred more than half of Iran's population (also going on to sack Baghdad, the centre of early Islamic culture). Descendants of Khan continued to quell uprisings for years, eventually reducing the population from 2.5 million to 250,000 over 40 years. The Black Death later wiped out another third. These huge setbacks took hundreds of years to recover from once Islamic rule was regained.

First Iranian female pilot Sadiqeh Dowlatshahi

Moving to the 20th century, First-World-War-weakened Qajar Dynasty was overthrown by army commander Reza Shah in 1921, who set about modernising Iran. He hired foreign consultants to help consolidate the country's infrastructure, linking railroads, improving health care and establishing a public education system. He also implemented the Woman's Awakening in the 30s, which required that they discard their veils, and opened doors to employment and education.

The Shah declared Iran neutral during World War II, and refused pressure from Russia to allow the transit of Allied arms through the country. As a result, Britain and Russia invaded and forced the Shah to abdicate the throne in favour of his son. They were then able to regain oil resources which the Shah had taken from British companies, and use the country for non-military war efforts.

Mohammed Mossadeq under house arrest

The first democratic elections in 20 years resulted in Mohammed Mossadeq rising to power in 1951, largely on the back of his policy to nationalise the oil fields which had been co-opted by Britain during the war. Britain was unhappy about losing the massive oil profits and, with American assistance, soon planned a coup d'état. It was to be the CIA's first, but they carried it off with flair, paying fake protesters on both sides to stimulate unrest.

Fazlollah Zahedi was installed as Prime Minister - a man who had been arrested by the Allies during WWII for trying to establish a pro-Nazi government. So in less than a decade Britain had once invaded Iran out of fear that they might ally with the Nazis, and again in order to put a sympathiser in power.

Shah Reza Pahlavi (son of the first Shah) was involved in the coup, and subsequently his power increased. By the 1970s he had abolished the multi-party political system in favour of a single sponsored party with forced national membership. The Iranian Revolution should not therefore have come as a surprise. Shia cleric Ayatollah Khomeini, who opposed the Shah's equality reforms for women and religious minorities, led protests that would last two years.

Jaleh Square, Black Friday 1978

Despite the Shah's pro-American stance for years, the US did not come to his aid. In desperation he banned demonstations (a measure recently echoed by the current Ahmadinnerjacket), and eventually introduced martial law, which culminated in the shooting of dozens of protesters on Black Friday. This final act of despotism sealed his fate, and in February 1979 Khomeini returned to Iran from exile and took power, creating an Islamic state, and bringing Sharia law into force.

Supreme Leader Ayatollah Khomeini brought into power the theocratic Guardian Council who have veto over the democratically elected parliament. He was succeeded a decade later by current Supreme Leader Ayatollah Khamenei. Whatever the resolution of the current elections, the continuing civil unrest, despite orders from the Ayatollah to cease protests, shows that opposition to the Supreme Leader is growing.

Bomb blast at Zahedan mosque, 2009