Born in Tehran, to Reza Khan (later Reza Shah Pahlavi) and his second wife, Tadj ol-Molouk, Mohammad Reza was the eldest son of Reza Khan, who later became the first Shah of the Pahlavi dynasty, and the third of his eleven children. His father, a former Brigadier-General of the Persian Cossack Brigade, was of Mazandarani and Georgian origin. His father was born in Alasht, Savadkuh County, Māzandarān Province. Mohammad Reza's paternal grandmother, Noush-Afarin, was a Muslim immigrant from Georgia (then part of the Russian Empire), whose family had emigrated to mainland Iran after Iran was forced to cede all of its territories in the Caucasus following the Russo-Persian Wars several decades prior to Reza Khan's birth. Mohammad Reza's mother, Tadj ol-Molouk, was of Azerbaijani origin, being born in Baku, Russian Empire (now Azerbaijan).
Crown Prince Mohammad Reza in 1939
Mohammad Reza was born along with his twin sister, Ashraf. However, Shams, Mohammad Reza, Ashraf, Ali Reza, and their older half-sister, Fatimeh, were not royalty by birth, as their father did not become Shah until 1925. Nevertheless, Reza Khan was always convinced that his sudden quirk of good fortune had commenced in 1919 with the birth of his son who was dubbed khoshghadam (bird of good omen). Like most Iranians at the time, Reza Khan did not have a surname and after the 1921 Persian coup d'état which deposed Ahmad Shah Qajar, he was informed that he would need a name for his house. This led Reza Khan to pass a law ordering all Iranians to take a surname; he chose for himself the surname Pahlavi, which is the name for the Middle Persian language, itself derived from Old Persian. At his father's coronation on 24 April 1926, Mohammad Reza was proclaimed Crown Prince.
Mohammad Reza described his father in his book Mission for My Country as "one of the most frightening men" he had ever known, depicting Reza Khan as a dominating man with a violent temper. A tough, fierce, and very ambitious soldier who became the first Persian to command the elite Russian-trained Cossack Brigade, Reza Khan liked to kick subordinates in the groin who failed to follow his orders; growing up under his shadow, Mohammad Reza was a deeply scarred and insecure boy who lacked self-confidence.
Mohammad Reza with his twin sister, Ashraf
, in the 1940s
Reza Khan believed if fathers showed love for their sons, it caused homosexuality later in life, and to ensure his favourite son was heterosexual, denied him any love and affection when he was young, though he later become more affectionate towards the Crown Prince when he was a teenager. Reza Khan always addressed his son as shoma ("sir") and refused to use more informal tow ("you"), and in turn was addressed by his son using the same word. The Polish journalist Ryszard Kapuściński observed in his book Shah of Shahs that looking at old photographs of Reza Khan and his son, he was struck by how self-confident and assured Reza Khan appeared in his uniform while Mohammad Reza appeared nervous and jittery in his uniform standing next to his father. In the 1930s, Reza Khan was an outspoken admirer of Hitler, though this was less because of any racism and anti-Semitism on his part, but rather because Reza Khan saw Hitler as someone much like himself, namely a man who had risen from an undistinguished background to become a notable leader of the 20th century. Reza Khan often impressed on his son his belief that history was made by great men such as himself, and that a real leader is an autocrat. Reza Khan was a huge barrel-chested and muscular man towering at over 6 feet 4 inches (1.93 m), leading his son to liken him to a mountain, and throughout his life, Mohammad Reza was obsessed with height and stature, for example wearing elevator shoes to make himself look taller than he really was, often boasting that Iran's highest mountain Mount Demavand was higher than any peak in Europe or Japan, and he was always most attracted to tall women. As Shah, Mohammad Reza constantly disparaged his father in private, calling him a thuggish Cossack who achieved nothing as Shah, and most notably the son almost airbrushed his father out of history during his reign, to the point that the impression was given the House of Pahlavi began its rule in 1941 rather than 1925.
The Iranian and Egyptian imperial families after a wedding in Saadabad Palace
, Tehran, 25 April 1939
Mohammad Reza's mother, Tadj ol-Molouk was an assertive woman who was also very superstitious. She believed that dreams were messages from another world, sacrificed lambs to bring good fortune and scare away evil spirits, and clad her children with protective amulets to ward off the power of the evil eye. Tadj ol-Molouk was the main emotional support to her son, cultivating a belief in him that destiny had chosen him for great things, as the soothsayers she consulted had explained her dreams as proving just precisely that. Mohammad Reza grew up surrounded by women, as the main influences on him were his mother, his older sister Shams and his twin sister Ashraf, leading the American psychologist Marvin Zonis to conclude it was "... from women, and apparently from women alone" that the future Shah" "received whatever psychological nourishment he was able to get as a child". Traditionally, male children were considered preferable to females, and as a boy, Mohammad Reza was often spoiled by his mother and sisters. Mohammad Reza was very close to his twin sister Ashraf as she noted: "It was this twinship and this relationship with my brother that would nourish and sustain me throughout my childhood ... No matter how I would reach out in the years to come-sometimes even desperately-to find an identity and a purpose of my own, I would remain inextricably tied to my brother ... always, the center of my existence was, and is, Mohammad Reza".
After becoming Crown Prince, Mohammad Reza was taken away from his mother and sisters to be given a "manly education" by officers selected by his father, who also ordered that everyone including his mother and siblings were to address the Crown Prince as "Your Highness". The result of his upbringing between a loving, if possessive and superstitious mother and an overbearing martinet father was to make Mohammad Reza in the words of Zonis "... a young man of low self-esteem who masked his lack of self-confidence, his indecisiveness, his passivity, his dependency and his shyness with masculine bravado, impulsiveness, and arrogance", making him into a person of marked contradictions as the Crown Prince was "both gentle and cruel, withdrawn and active, dependent and assertive, weak and powerful".
By the time Mohammad Reza turned 11, his father deferred to the recommendation of Abdolhossein Teymourtash, the Minister of Court, to dispatch his son to Institut Le Rosey, a Swiss boarding school, for further studies. Mohammad Reza left Iran for Switzerland on September 7, 1931. On his first day as a student at Le Rosey in September 1931, the Crown Prince antagonised a group of his fellow students who were sitting on a bench in a park outside Le Rosey with his demand that they all stand to attention as he walked past, just as everybody did back in Iran, which led to an American student beating up Mohammad Reza, who swiftly learned to accept that no one would stand to attention wherever he went in Switzerland. As a student, Mohammad Reza played competitive football, but the school records indicate that his principal problem as a football player was his "timidity" as the Crown Prince was afraid to take risks. The Crown Prince was educated in French at Le Rosey, and his time there left Mohammad Reza with a lifelong love of all things French. In articles he wrote in French for the student newspaper in 1935 and 1936, Mohammad Reza praised Le Rosey for broadening his mind and introducing him to European civilisation. Mohammad Reza lost his virginity to a maid who worked at Le Rosey in 1935.
Mohammad Reza was the first Iranian prince in line for the throne to be sent abroad to attain a foreign education and remained there for the next four years before returning to obtain his high school diploma in Iran in 1936. After returning to the country, the Crown Prince was registered at the local military academy in Tehran where he remained enrolled until 1938, graduating as a Second Lieutenant. Upon graduating, Mohammad Reza was quickly promoted to the rank of Captain, a rank which he kept until he became Shah. During college, the young prince was appointed Inspector of the Army and spent three years travelling across the country, examining both civil and military installations.
Mohammad Reza spoke English, French and German fluently in addition to his native language Persian.
During his time in Switzerland, Mohammad Reza befriended Ernest Perron, the son of a Perron, who fancied himself a poet introduced Mohammad Reza to French poetry and under his influence Chateaubriand and Rabelais became his "favorite French authors". The Crown Prince liked Perron so much that when he returned to Iran in 1936, he brought Perron back with him, installing his best friend in the Marble Palace. Perron lived in Iran until his death in 1961 and as the best friend of Mohammad Reza was a man of considerable behind-the-scenes power. After the Islamic Revolution in 1979, a best-selling book was published by the new regime, Ernest Perron, the Husband of the Shah of Iran by Mohammad Pourkian, alleging a homosexual relationship between the Shah and Perron, which remains the official interpretation in the Islamic Republic to the present day. Zonis described the book as long on assertions and short on evidence of a homosexual relationship between the two, noted that all of the Shah's courtiers denied that Perron was the Shah's lover, and argued that strong-willed Reza Khan, who was very homophobic, would not have allowed Perron to move into the Marble Palace in 1936 if he believed Perron was his son's lover.