History of Strait of Hormuz in Timeline

By Popular Timelines Editorial Team · Updated: July 12, 2026

The Strait of Hormuz is a vital maritime chokepoint connecting the Persian Gulf with the Gulf of Oman and the Arabian Sea. Situated between Iran to the north and the United Arab Emirates and Oman to the south, it serves as the world's most significant oil transit artery. Approximately 20% of global petroleum consumption passes through this narrow waterway, making it strategically indispensable to international energy security and the global economy. Due to its narrow width, shipping traffic is funneled into two-mile-wide lanes in each direction. The strait has long been a focal point of geopolitical tension, frequently serving as a site for military posturing and diplomatic disputes between Iran and various Western nations. Any major disruption or closure of this passage could cause severe spikes in global oil prices and jeopardize the stability of international trade routes, solidifying its status as a critical node in global geopolitics.

1959: Iran Alters Territorial Sea Status

In 1959, Iran expanded its territorial sea to 12 nautical miles (22 km) and declared that it would only permit innocent passage through these newly claimed waters within the Strait of Hormuz.

1971: Iranian Occupation of Greater and Lesser Tunbs

In 1971, Iran seized control of the Greater and Lesser Tunbs islands located west of the Strait of Hormuz, an action taken against the wishes of Arab nations that strengthened Iran's strategic control over regional navigation channels.

1972: Full Closure of the Strait by Territorial Waters

Following Oman's 1972 decree to expand its territorial sea to 12 nautical miles, the overlapping waters of Iran and Oman effectively enclosed the Strait of Hormuz within their combined territorial jurisdiction.

May 1981: Initiation of Iraqi attacks on commercial shipping

Starting in May 1981, Iraq launched a military campaign targeting commercial vessels associated with Iran to weaken their war efforts. Initially, the strikes focused on ships carrying military supplies for the Iranian ground forces, but the scope eventually grew to include vessels transporting Iranian exports, which prompted retaliatory strikes from Iran against ships belonging to Iraq's trading partners.

1981: Omani Royal Decree on Territorial Waters

In 1981, Oman issued a royal decree asserting that foreign warships must obtain prior permission before navigating through Omani territorial waters, a stance that deviated from customary maritime law of the era.

1982: Iran's Declaration on the Law of the Sea Convention

In 1982, upon signing the Law of the Sea Convention, Iran issued a declaration stating that the treaty's contractual rights, specifically transit passage through international straits, were exclusively reserved for signatory states.

1984: Escalation of the Tanker War

In 1984, Iraq expanded the scope of the Tanker War by launching attacks on the oil terminal and shipping vessels located at Kharg Island. In retaliation, Iran initiated a campaign targeting oil tankers associated with Kuwait and other Gulf Arab nations that were providing support to Iraq's military operations throughout 1984.

April 1988: Operation Praying Mantis

On 18 April 1988, the United States Armed Forces launched Operation Praying Mantis against Iranian targets in Iranian territorial waters. This military action was a retaliatory strike following the mining of international waters by Iran and the resulting damage to an American warship during the Iran-Iraq War. The operation involved coordinated surface warship strikes and aerial support from the USS Enterprise carrier group.

July 1988: Iran Air Flight 655 Shootdown

On 3 July 1988, an Iran Air Airbus A300 civilian passenger plane was shot down over the Strait of Hormuz by the U.S. Navy guided missile cruiser USS Vincennes (CG-49), resulting in the deaths of 290 people after the crew mistakenly identified the aircraft as a hostile jet fighter.

1989: Oman Ratifies UNCLOS

In 1989, Oman ratified the United Nations Convention on the Law of the Sea (UNCLOS), submitting official declarations that reinforced a previous royal decree stipulating that only innocent passage is allowed through its territorial sea and requiring prior authorization for foreign warships.

1993: Enactment of Iran's Maritime Areas Law

In 1993, Iran passed a domestic maritime law that conflicted with UNCLOS regulations by requiring warships, submarines, and nuclear-powered vessels to seek prior authorization before navigating through its territorial waters.

2005: Origin of Legal Dispute over Container Boxes

In 2005, a commercial dispute occurred involving 10 container boxes transported to Dubai, which eventually served as the legal catalyst for the 2015 detention of the MV Maersk Tigris by Iranian authorities.

January 2007: Collision between USS Newport News and MV Mogamigawa

In January 2007, the United States nuclear submarine USS Newport News collided with a Japanese oil tanker named MV Mogamigawa located south of the Strait of Hormuz. Fortunately, the incident resulted in no injuries to the crews and caused no environmental damage from oil leaks.

December 2007: Naval stand-offs between Iran and the U.S.

In December 2007, a series of naval stand-offs occurred in the Strait of Hormuz involving Iranian speedboats and United States warships, leading to accusations of harassment from U.S. officials which Iran subsequently denied.

January 2008: Escalation and contradiction of naval engagement reports

Throughout January 2008, tensions remained high as the Pentagon claimed U.S. vessels nearly fired on Iranian boats, a narrative challenged on 14 January 2008 by Vice Admiral Kevin Cosgriff, who downplayed the threat posed by the Iranian small boats.

March 2009: Collision of USS Hartford and USS New Orleans

On 20 March 2009, a collision occurred within the Strait of Hormuz involving the U.S. Navy submarine USS Hartford and the amphibious transport dock USS New Orleans. The impact damaged the hull of the USS New Orleans, leading to a significant spill of 95 cubic meters of marine diesel fuel into the surrounding waters.

December 2011: Iranian Threat to Close Strait of Hormuz

On December 27, 2011, Iranian Vice President Mohammad Reza Rahimi threatened to block oil shipments through the Strait of Hormuz in response to international economic sanctions. While Iranian military officials claimed the act would be easy to execute, the U.S. Fifth Fleet maintained readiness to prevent such actions. Although oil prices initially rose by 2%, market reaction remained limited due to the significant presence of U.S. military hardware in the region, which experts argued would make a prolonged blockade impossible.

2011: Baseline Oil Purchase Levels

In 2011, China maintained a specific volume of oil purchases from Iran, which served as the baseline for the significant 50% reduction implemented by China in January 2012.

2011: Daily Crude Oil Transit Volumes

In 2011, the Strait of Hormuz saw an average of 14 tankers departing the Persian Gulf daily, transporting 17 million barrels of crude oil, with over 85% directed toward key Asian markets such as Japan, India, South Korea, and China.

January 2012: Diplomatic Tensions Regarding the Strait of Hormuz

During January 2012, diplomatic friction intensified as Iran's Defense Minister Ahmad Vahidi denied threats to close the Strait of Hormuz on 9 January 2012, emphasizing Iran's role in regional security. Subsequently, on 16 January 2012, Iran confirmed receipt of a formal letter from the United States regarding the strait, following prior U.S. warnings that any attempt to close the waterway would be considered a 'red line' triggering an American response.

January 2012: Impact of Iranian Sanctions on Oil Markets

In January 2012, crude oil futures rose by over 4% due to heightened geopolitical tensions and economic sanctions against Iran. This price surge was significantly influenced by China's decision to cut its oil imports from Iran by 50% compared to levels seen in 2011.

January 2012: Escalation of Economic Sanctions on Iran

In January 2012, the Iranian currency experienced a 12% devaluation due to the economic impact of sanctions led by the United States. During the same month, French Foreign Minister Alain Juppé advocated for the European Union to intensify these measures by freezing Iranian central bank assets and implementing an oil export embargo.

January 2012: Iranian threat to U.S. Navy aircraft carrier

On 3 January 2012, Iranian Army chief Ataollah Salehi issued a stern warning to the United States military, stating that Iran would take retaliatory action if an American aircraft carrier returned to the Persian Gulf after having relocated to the Gulf of Oman during Iranian naval exercises.

July 2018: Iranian Threats to Close the Strait of Hormuz

In July 2018, the Iranian government issued threats to close the Strait of Hormuz in response to the United States' withdrawal from the Joint Comprehensive Plan of Action (JCPOA) and the subsequent reimposition of economic sanctions against Iran.

2018: Peak Daily Oil Flow

During 2018, the volume of oil transported through the Strait of Hormuz reached 21 million barrels per day.

2019: U.S. Assessment of Iranian Naval Mine Capabilities

In 2019, the U.S. Defense Intelligence Agency released an estimate stating that Iran held a stockpile of more than 5,000 naval mines, designed for quick deployment using high-speed watercraft.

2019: Valuation of 2018 Oil Transit

In 2019, the economic value of the 21 million barrels of oil that passed through the strait daily in 2018 was calculated to be $1.2 billion based on 2019 market prices.

May 2020: Iranian Friendly Fire Missile Incident

In May 2020, a tragic friendly fire incident occurred when Iran accidentally launched missiles at one of its own naval ships, resulting in the loss of 19 sailors.

January 2021: Seizure of the Hankuk Chemi tanker

On 4 January 2021, Iranian forces seized the South Korea–flagged oil tanker Hankuk Chemi in the Strait of Hormuz due to alleged pollution violations. The vessel, which had departed from Jubail, Saudi Arabia on 2 January 2021 carrying 7,000 tons of ethanol, was subsequently detained while en route to Fujairah, United Arab Emirates.

June 2021: Sinking of the IRIS Kharg

On June 2, 2021, the IRIS Kharg, which served as the largest vessel in the Iranian Navy, caught fire and subsequently sank in the Strait of Hormuz.

2023: Annual throughput of global energy resources through the Strait of Hormuz

During the year 2023, the Strait of Hormuz maintained its role as a critical maritime choke point, facilitating the transit of 20% of the world's liquefied natural gas and 25% of the total seaborne oil trade.

2023: Strait of Hormuz Trade Significance

In 2023, the Strait of Hormuz solidified its status as a critical maritime chokepoint, facilitating the passage of 20% of the global supply of liquefied natural gas and 25% of the world's seaborne oil trade.

April 2024: Iranian Navy Seizes MSC Aries

In April 2024, the Iranian Navy intercepted and seized the Portuguese-flagged container ship MSC Aries near the Gulf of Oman, off the coast of Fujairah. The vessel, which carried 25 crew members of various nationalities, was forcibly steered through the Strait of Hormuz by Iranian forces under the pretext of alleged maritime law violations.

June 2025: Detection of Iranian Naval Mine Loading

During June 2025, U.S. intelligence identified Iranian military forces loading naval mines onto ships in the Persian Gulf. While these mines were never deployed, the June 2025 observation led to significant concerns in Washington regarding a potential attempt by Tehran to blockade the Strait of Hormuz.

2025: Continued Strategic Importance of the Strait

Throughout 2025, the Strait of Hormuz remained a vital artery for global commerce, continuing to manage the transit of 20% of the world's liquefied natural gas and 25% of all seaborne oil trade.

2026: 2026 Strait of Hormuz Crisis

During the 2026 Iran War, Iranian forces initiated blockades of the Strait of Hormuz, leading to a significant geopolitical crisis in 2026 as this was the first time the strait saw an extended closure during modern Middle East conflicts.

28 April 2015: Interception of MV Maersk Tigris by Iranian Forces

On 28 April 2015, the Iranian Revolutionary Guard Corps Navy intercepted the Marshall Islands-flagged container ship MV Maersk Tigris in the Strait of Hormuz. After the ship's captain initially refused orders to enter Iranian waters, Iranian forces fired warning shots, forcing the vessel to divert to Larak Island. The U.S. Navy deployed the USS Farragut and aircraft to monitor the event, which stemmed from a legal dispute involving a $3.6 million court-ordered fine.