Question: The current longtime Supreme Leader of Iran was born in which year ?

Context paragraphs:
Assembly of Experts: The Assembly of Experts (Persian: مجلس خبرگان رهبری‎ , "Majles-e Khobregān-e Rahbari " ‎ ) —also translated as the Assembly of Experts of the Leadership or as the Council of Experts— is the deliberative body empowered to designate and dismiss the Supreme Leader of Iran.  However all directly-elected members after the vetting process by the Guardian Council still have to be approved by the Supreme Leader of Iran before gaining membership to the Assembly of Experts.

Succession of Ali Khamenei: The succession of Ali Khamenei, the current Supreme Leader of Iran, has been a taboo in Iran.  According to the Constitution of the Islamic Republic of Iran, the Supreme Leader is elected by two third majority of the Assembly of Experts members.  however, the Assembly has not elected any deputies since the deposition of Hussein-Ali Montazeri in 1987.  The Assembly elected a Supreme Leader once in the Iranian Supreme Leader election, 1989.

Supreme Leader of Iran: The Supreme Leader of Iran (Persian: رهبر معظم ایران‎ , "rahbar-e mo'azzam-e irān " ‎ ), also called the Supreme Leader of the Islamic Revolution (رهبر معظم انقلاب اسلامی , "rahbar-e mo'azzam-e enghelāb-e eslāmi "), officially in Iran, called the Supreme Leadership Authority (مقام معظم رهبری , "maqām mo'azzam rahbari "), is the head of state and highest ranking political and religious authority in the Islamic Republic of Iran.  The armed forces, judicial system, state television, and other key governmental organizations are under the control of the Supreme Leader of Iran.  The current longtime Supreme Leader of Iran, Ali Khamenei, has been issuing decrees and making the final decisions on economy, environment, foreign policy, education, national planning, and everything else in Iran.  Khamenei also makes the final decisions on the amount of transparency in elections in Iran, and has fired and reinstated Presidential cabinet appointments.  Iran’s regional policy is directly controlled by the office of the Supreme Leader with the Ministry of Foreign Affairs’ task limited to protocol and ceremonial occasions.  All of Iran’s ambassadors to Arab countries, for example, are chosen by the Quds Corps, which directly reports to the Supreme Leader.

Ali Khamenei: Sayyid Ali Hosseini Khamenei (Persian: سید علی حسینی خامنه‌ای‎ ‎ ] ; born 17 July 1939) is a "marja" and the second and current Supreme Leader of Iran.  Khamenei succeeded the first Supreme Leader, Ruhollah Khomeini, after Khomeini's death, being elected as the new Supreme Leader by the Assembly of Experts on 4 June 1989 at the age of 49.  His political career began after the Iranian Revolution, when the former President of Iran, Akbar Hashemi Rafsanjani, then a confidant of Khomeini, brought Khamenei into Khomeini's inner circle.  Later on, the current President of Iran, Hassan Rouhani, then a member of Parliament, arranged for Khamenei to get his first major post in the provisional revolutionary government as deputy defense minister.  Khamenei then went to serve as the third President of Iran from 1981 to 1989 while becoming a close ally to Khomeini.  Eventually, after Khomeini had a fall off with then heir-apparent Hussein Ali Montazeri, Rafsanjani claimed that Khomeini had chosen Khamenei as his successor while the Assembly of Experts deliberated to elect the next Supreme Leader.  Khamenei is head of the servants of Astan Quds Razavi from April 14, 1979.

List of Iranian presidential elections: The tenth Iranian presidential election to be held in Iran.  The President of Iran is the highest official elected by direct, popular vote, although the President carries out the decrees, and answers to the Supreme Leader of Iran, who functions as the country's head of state.  Unlike the executive in other countries, the President of Iran does not have full control over anything, as these are ultimately under the control of the Supreme Leader.  Chapter IX of the Constitution of the Islamic Republic of Iran sets forth the qualifications for presidential candidates.  The procedures for presidential election and all other elections in Iran are outlined by the Supreme Leader.  The President functions as the executive of the decrees and wishes of the Supreme Leader.  These include signing treaties and other agreements with foreign countries and international organizations, with Supreme Leader's approval; administering national planning, budget, and state employment affairs, as decreed by the Supreme Leader.  The President also appoints the ministers, subject to the approval of Parliament, and the Supreme Leader who can dismiss or reinstate any of the ministers at any time, regardless of the president or parliament's decision.

Government of Islamic Republic of Iran: Government of Islamic Republic of Iran is the name given to the Iranian government after the Islamic revolution.  Two months after the victory of Iranian revolution in a referendum more than 98% of Iranian voters approved this name for their government.  This government is one of the kinds of Islamic republic and it political structure includes the supreme leader, and the executive , legislative and the Judicial system and Assembly of Experts, Expediency Discernment Council and City and Village Councils of Iran are other institutes of this government.  The Supreme Leader is the commander-in-chief of Iran.

President of Iran: The President of Iran (Persian: رییس‌جمهور ایران "Rayis Jomhur-e Irān") is the head of government of the Islamic Republic of Iran.  The President is the highest popularly elected official in Iran (however, the president is still required to gain the Leader’s official approval before being sworn in before the Parliament, and the Leader also has the power to dismiss the elected president anytime).  The President carries out the decrees, and answers to the Supreme Leader of Iran, who functions as the country's head of state.  Unlike the executive in other countries, the President of Iran does not have full control over anything, as these are ultimately under the control of the Supreme Leader.  Chapter IX of the Constitution of the Islamic Republic of Iran sets forth the qualifications for presidential candidates.  The procedures for presidential election and all other elections in Iran are outlined by the Supreme Leader.  The President functions as the executive of the decrees and wishes of the Supreme Leader.  These include signing treaties and other agreements with foreign countries and international organizations, with Supreme Leader's approval; administering national planning, budget, and state employment affairs, as decreed by the Supreme Leader.  The President also appoints the ministers, subject to the approval of Parliament, and the Supreme Leader who can dismiss or reinstate any of the ministers at any time, regardless of the president or parliament's decision.  Iran’s regional policy is directly controlled by the office of the Supreme Leader with the Ministry of Foreign Affairs’ task limited to protocol and ceremonial occasions.  All of Iran’s ambassadors to Arab countries, for example, are chosen by the Quds Corps, which directly reports to the Supreme Leader.

Iranian Police Ideological−Political Organization: Ideological−Political Organization or Bureau of NAJA (Persian: سازمان عقیدتی سیاسی ناجا‎ ‎ ; "Aghidati-Siasi") is one of three virtually independent hierarchical systems inside Law Enforcement Force of Islamic Republic of Iran, alongside its Command system (led by the Chief Police Commander) and the Intelligence Protection Organization.  Director of the organization is directly appointed by the Supreme Leader of Iran.  The Ideological−Political organizations of Iranian armed forces are taught to indoctrinate the personnel with Islamic and political training aligned with the Supreme Leader's guidelines.  The organization is supervised by clerics.

Office of the Supreme Leader of Iran: House of Leadership (Persian: بیت رهبری‎ ‎ , "Beit-e Rahbari"; official name: Office of the Supreme Leader of Iran (Persian: دفتر مقام معظم رهبری‎ ‎ ); "Daftar-e Magham-e Moazzam-e Rahbari") is the official residence, bureaucratic office and principal workplace of the Supreme Leader of Iran since 1989.

Media of Iran: The Media of Iran are privately and publicly owned but is subject to censorship.  As of 2016, Iran had 178 newspapers, 83 magazines, 15,000 information sites and 2 million blogs.  A special court has authority to monitor the print media and may suspend publication or revoke the licenses of papers or journals that a jury finds guilty of publishing anti-religious material, slander, or information detrimental to the national interest.  The Iranian media is prohibited from criticizing the Islamic doctrines (as interpreted by the Iranian regime), former leader Ruhollah Khomeini, and current longtime leader Ali Khamenei.

Supporting paragraphs: Supreme Leader of Iran Ali Khamenei
Answer: 1939