After overthrowing Mossadeq, the Anglo-Iranian Oil Company (AIOC) was renamed the British Petroleum Company (BP) in 1954

In 1901, Persia's (later renamed Iran) then corrupt ruler Muzaffar al-Din Shah signed away a 60-year exclusive right to explore and excavate oil in southern Iran to a London-based financier William Knox D'Arcy.  For a pittance. Twenty thousand British pounds, fifty percent of the shares in D'Arcy's future company and 16% of its profits -- to help pay for al-Din Shah's "extravagant lifestyle."
The Anglo-Persian Oil Company (APOC) was founded in 1908 with the addition of new investors; the British government bought 51% of the company's shares in 1913 for £2 million. From then on, "the interests of the company and the British government were joined at the hip" (Phil Wilayto, Monthly Review Press, June 30, 2010).
BP's oil exploration and production in southern Iran was built along classic colonial and racist lines, for, while British employees lived in "well built homes with access to tennis courts and swimming pools", Iranian oil workers were treated with contempt, Wages were 50 cents a day. There was no vacation pay, no sick leave, no disability compensation. The workers lived in a shanty town called Kaghazabad, or Paper City, without running water or electricity ... In winter the earth flooded... The mud in town was knee-deep....Summer was worse...The dwellings of Kaghazabad, cobbled from rusted oil drums hammered flat, turned into sweltering ovens. ... In every crevice hung the foul, sulfurous stench of burning oil .... in Kaghazad there was nothing -- not a tea shop, not a bath, not a single tree. (from Manucher Farmanfarmaian's Blood and Oil: Inside the Shah's Iran, Farmanfarmaian became director of Iran's petroleum institute in 1949: quoted in Stephen Kinzer, All the Shah’s Men: An American Coup and the Roots of Middle Eastern Terror, 2003).
Things came to a head in July 1946, when 6,000 Iranian workers went on a strike in Agajari and clashes with government troops led to deaths and injuries of 200 people.
In the late 1940s, Mosaddeq had founded Jebhe Melli (National Front of Iran) to establish democracy and to end foreign presence in Iranian politics, especially by nationalising AIOC operations in Iran. "The moral aspect of oil nationalization is more important than its economic aspect." He demanded that AIOC open its books for inspection, that Iranians be trained for technical jobs so that they could learn to run the Abadan refinery -- but the British government refused. After being elected the head of the parliament's oil committee, Mosaddeq demanded that Iran should receive half of the profits (US Aramco had by then agreed to 50-50 profit-sharing with Saudi Arabia) -- but the British government refused.
The nationalisation law -- passed by all members of the Majlis soon after Mosaddeq was appointed prime  minister -- brought him into a head-on conflict with Britain, even though the latter's Labour government was nationalising its own coal, electric, rail and steel industries.
The British adopted a three-track strategy aimed at pressurising Mosaddeq to accept terms favorable to them, if not, to have him removed from office:
(i)     a series of legal manoeuvres (including arbitration by the International Court of Justice at The Hague; the court later ruled that the dispute lay outside its jurisdiction)
(ii)    undermining Mosaddeq's base of support by imposing economic sanctions on Iran and conducting military manoeuvres in the region (AIOC threatened anyone buying Iranian  oil with legal action; the British imposed an embargo on exports to Iran including iron, steel, sugar, oil processing equipment)
(iii)    attempting to remove Mosaddeq from office through covert political action, involving a network of pro-British politicians, businessmen, military officers and religious figures (Gasiorowski, International Journal of Middle East Studies, 19, 1987).
What Iranian oil meant to the British economy and the British way of life is described very aptly by Kinzer in an interview to DemocracyNow,
...the oil that fueled England all during the 1920s and '30s and ’40s all came from Iran. The standard of living that people in England enjoyed all during that period was due exclusively to Iranian oil. Britain has no oil. Britain has no colonies that have oil. Every factory in England, every car, every truck, every taxi was running on oil from Iran. The Royal Navy, which was projecting British power all over the world, was fueled a hundred percent by oil from Iran (May 6, 20120).
But it is Fariborz Mokhtari who captures what Iranian oil meant to the British psyche. "Iran’s oil was by right British oil" because they had "discovered, exploited, refined, transported, and marketed it." That the oil was located on Iranian soil, hence, it rightfully belonged to the Iranians was a fact "of little consequence" to most British politicians. Anthony Eden -- despite having studied Persian at Oxford, despite having a soft spot for Persian culture -- denounced the Iranians in 1951 for "stealing British property" (emphasis mine).
In 1951, Mossadeq travelled to the United States to garner American and international support. In his address to the United Nations, he pointed out how Iran was being cheated, 
To give you an idea of Iran’s profits from this enormous industry, I may say that in 1948, according to accounts of the former Anglo-Iranian Oil Company, its net revenue amounted sixty-one million pounds; but from those profits Iran received only nine million pounds, although twenty-eight million pounds went into the United Kingdom treasury in income tax alone…" (quoted in Kinzer, All the Shah’s Men).
The outgoing Truman administration, which was "ostensibly neutral", in reality supported the British boycott. In January 1953, president Dwight D. Eisenhower took office and asserted that Truman's containment policy did not go far enough, that a more aggressive policy was needed against world communism. Within two months, the concept of a joint US-British operation to remove Mosaddeq from office was officially approved. Code-named TPAJAX, the planned coup went operational in mid-August.
After the coup, says Gasiorowski, Iran's halting progress since the early 1900s "toward a more representative form of government and toward freedom from foreign interference" came to an end.
The Shah's authoritarian regime was gradually consolidated, it received massive US assistance (between 1959 and 1971, aggregate US arms sales to Iran totaled $1.8 billion, Lyn Boyd, 2000), martial law was instituted and remained in effect for many years, thousands of National Front and Tudeh supporters were arrested, pro-Mosaddeq demonstrations in Tehran were crushed, the National Resistance Movement (successor to the National Front) was suppressed, leaders of the Qashqai tribe were attacked and exiled, press censorship was introduced, a secret police force was formed which gradually evolved into the much-hated SAVAK, the 1954 Majlis elections were blatantly rigged. These combined to extinguish all opportunities for developing "even a moderate political opposition in Iran."
Because of America's role in the coup, many Iranians viewed Washington -- the Shah's all-powerful patron -- as being  the Great Satan; these experiences and perceptions helped shape and forge the anti-American character of the 1978-79 Islamic revolution in Iran. Other anti-American incidents as well, culminating in the US embassy hostage crisis (Gasiorowski, Byrne).
While the rest is history, it is a history that is currently repeating itself, as US-led western powers and Israel -- to reverse the 'blowback' from the coup which they had organised in 1953? -- to all intents and purposes prepare for a military attack on Iran, albeit, one worthy of 21st century standards:
--     Iran has been surrounded by American military bases which are continually being built up
--     a new missile defense radar station has been built at a secret site in Qatar
--     a new US elite commando team is operating in the region
--     the US and Europe are helping Gulf nations modernise their militaries, for instance, deals have been signed with Saudia Arabia to purchase 84 brand new Boeing F-15SA Strike Eagle fighter-bombers; to upgrade 70 of the kingdom's existing F-15S Strike Eagles; to purchase 72 brand new Eurofighter Typhoons (24 have already been delivered); to purchase three stealthy air-defense frigates from France
--     there is an enormous and a still growing presence of US naval forces in the Persian Gulf including two aircraft carrier battle groups, minesweepers, a new floating base for possible special operations forces, and tiny drone submersibles
--     a large scale build-up of US air power is evident as well, including deployment of the most advanced US fighter plane, the F-22, to a base in the United Arab Emirates
These are in addition to the crippling oil sanctions, the release of cyber worms to infect Iranian computer systems linked to its nuclear programme, the assassination of Iran's nuclear scientists -- all topped by the mainstream western media's "scattered, almost absent-minded" reporting of this insane military build-up, and a more insane attack (TomDisptach, August 12, 2012).
To return to the coup, on the morning of August 19th, crowds organised by the CIA team, possibly, also by MI6's main agents the Rashidian brothers, and by CIA's two principle agents code named Nerren and Cilley, were joined in by police and army units, and by onlookers angered by 'fake' Tudeh demonstrations or disillusioned with Mosaddeq. A pro-Zahedi army detachment and a column of tanks led by general Guilanshah of the Air Force, together with a group of pro-Shah demonstrators, marched on to Mosaddeq's home. A nine-hour battle, 300 people killed, the house destroyed by tank and artillery fire. Mosaddeq escaped but surrendered to Zahedi the following day (Gasiorowski, 1987).
The Shah, who had had fled the country, returned from Rome on August 22, 1953. Zahedi's new government agreed to give the US and Great Britain the lion's share of Iranian oil. Many of Mosaddeq's former associates were tried, imprisoned and tortured. Some were sentenced to death; Mosaddeq's minister of foreign affairs and closest associate was shot to death by a firing squad.
Mosaddeq was tried by the Shah's military court and convicted of treason at the age of 71. His death sentence was later commuted to three years solitary confinement in a military prison, and house arrest until his death on March 5, 1967.
But the `most cruel punishment', said Mosaddeq, was the trauma inflicted on his daughter. Thirteen-year old Khadijeh , who had witnessed her father's brutal arrest, was deeply traumatised by the incident and spent the rest of her life in psychiatric hospitals.
Mosaddeq's death wish had been to be buried in the cemetery of martyrs, but the Shah refused. He was buried instead in the ground of the dining room of his house in Ahmad-Abad.
At his trial, Mosaddeq remarked, "my greatest sin was that I nationalised Iran's oil industry and discarded the system of political and economic exploitation by the world's greatest empire."
When the oppressed and the colonised reclaim what is rightfully theirs, the much venerated western ideal of 'tolerance' snaps. Teeth bared, ugliness exposed. 
But history redeems.
For, it is Mosaddeq who is loved, admired and deeply respected. Not the shah, nor Zahedi, nor other quislings. Nor those who continue to covet the wealth of other nations.