Who was he: Reza Shah Pahlavi, known as Reza Shah, came to power in the Imperial State of Iran in 1925 when he overthrew the Ahmad Shah Qajar, the last of the Persian Qajar Dynasty, marking the beginning of the Pahlavi Dynasty. He was and is considered by many to be the Father of modern day Iran.
For clarity: Reza Shah's son, Mohammad Reza Shah Pahlavi, (1919-1980) was the last crown prince of Iran (Shah of Iran), who ruled from the time of his father's abdication until he himself abdicated the throne during the Iranian Revolution in 1979; Reza Shah's grandson, Reza Pahlavi, "Prince Pahlavi," was born in 1960, left Iran during the Revolution, and is currently Head of the Pahlavi Dynasty.
Reza Shah benefitted the nation of Iran by having brought about socio-economic programs that improved the lives of Iranian people. His reign lasted until 1941 when he was forced to abdicate in favor of his son by the Anglo-Soviet Invasion on the 16th of September. This action came in response to the Shah's declaration of neutrality in World War II and because he would not allow Iran to be used for movement of supplies from Britain to Russia in the war against Germany.
Shah Reza Khan is historically well-loved by many for the rapid and significant advances he brought to Iran's healthcare, education, civil rights, infrastructure, financial policies, workers' pay rights, etc. He is nonetheless disdained by some for the corruption that eventually marred his reign and the "iron first" he used to mete out harsh punishment for certain crimes.
Background: Born March 15, 1878, Reza Shah Pahlavi came into a world of wealth and stature, which in the final analysis meant very little to him. Reza's father, Major Abbas Ali Khan, from the prominent Ayrum Urum tribe, had five wives and ten children, and brought strong political and military beliefs to Iran in the late 1800s.
Reza Shah's father died in 1878 shortly after the birth of Reza. His mother and he moved to his uncle's house in Tehran. Being shuffled around in his early days from caretaker to caretaker, he eventually was raised by an army officer, Amir Tuman Kazim Khan. At that time, he took on the name of Khan.
At age 16 Reza joined the Persian Cossack Brigade and would eventually rise to the position of Brigadier General. Reza Khan was instrumental in leading an overthrow of the Qajar regime at a time of great weakness in the central government that left the country ripe for the taking. Khan became commander in chief of the army, a position he held until he became shah.
The coup was partially assisted by the British government in an attempt to prevent the Bolsheviks' takeover of Iran, When Reza Shah Pahlavi, Reza Khan, became The British were extremely concerned about the future of Iran. Their stake in India was possibly at risk, and according to the Russo-Persian Treaty of 1925, Russia was permitted to invade Persia if any of their territories were being threatened by factions within Persia. The British sent aid to Reza's military and began to formulate the details of the coup that would entirely overthrow the government.
Reza would first be known as King of Iran, according to the prevailing constitution. This was temporary, as Reza Pahlavi foresaw the establishment of a true republic in Iran's future. In 1935 he proclaimed that the country would hitherto be called Iran rather than Persia, as Persians represented only one of many ethnic groups within the boundaries of the State. This name change was a demand placed upon the whole world in an effort to appease all Iranian natives.
The new Shah wanted to quickly modernise the country. The number of industries and miles of highway increased at a rapid pace. Standards employed in healthcare were the most notable change, allowing Iran to look more like the Western world. The Shah wanted no pictures taken of the poorer, less developed areas of Iran. The rapidity with which he was moving the country forward was frightening to many and led to unrest.
Shah Mohammed Reza Pahlavi's reign was short-lived, though extremely important. On the 16th of September, 1941 he abdicated his throne during the Anglo-Soviet Invasion which took his beloved country from him and was exiled to various British Territories. He died several years later on the 26th of July, 1944 of heart disease. He was buried in a beautiful mausoleum in Iran, but his remains were moved to Cairo's Al Rafa'i Mosque where his son is also now buried.