Aden (; Arabic: عَدَنْ, romanised: ʿAdan; IPA: [ʕa.dan]) is an ancient port city in the southern part of the Arabian peninsula, on the north coast of the Gulf of Aden, positioned near the eastern approach to the Red Sea, and has been the de facto capital of Yemen since 2014. It is approximately 170 km (110 mi) east of the Bab-el-Mandeb strait. With its strategic location on the coastline, Aden serves as a gateway between the Red Sea and the Arabian Sea, making it a crucial maritime hub connecting Africa, Asia, and the Middle East.
In 2026 Aden had a population estimated at 1,194,160, making it one of the largest cities in Yemen. It is the capital and principal part of Aden Governorate, encompassing eight districts. During the colonial period, the name Aden referred to the area along the north coast of the gulf, encompassing Tawahi, Mualla, Crater, and much of Khor Maksar district. The western harbour peninsula, known as Little Aden, now falls within the Al Buraiqeh district.
The city and surrounding area were under British administration from 1839 until independence in 1967. Before gaining independence, Aden comprised distinct sectors: Crater, the original port; Ma'alla, the modern port; Tawahi, formerly "Steamer Point"; and Gold Mohur resorts. Khormaksar, on the isthmus connecting Aden to the mainland, hosts diplomatic missions, Aden University's main offices, and Aden International Airport. On the mainland, sectors include Sheikh Othman, an old oasis area; Al-Mansura, a British-planned town; and Madinat ash-Sha'b (formerly Madinat al-Ittihad), the former capital of the South Arabian Federation, now the location of a large power/desalination facility and additional Aden University faculties.
Aden encloses the eastern side of a vast natural harbour that constitutes the modern port. Little Aden was developed as the site of the oil refinery and tanker port. Both were established and operated by British Petroleum until they were turned over to South Yemeni government ownership and control in 1978.
Aden was the capital of South Yemen from 1967 until that state's union with North Yemen in 1990. It has been the temporary capital of Yemen since the start of the Yemeni civil war in 2014, hosting some members of the Cabinet of Yemen mainly in al-Maashiq Palace. It was also the seat of the secessionist Southern Transitional Council from 2018 to 2026.
Aden is a home and a place for ships, and in Arabic the word "Aden" means residence, and it is said "Aden Al-Balad", meaning the settlement of the country. Among the sayings of geographers about the city:
Yaqut al-Hamwi said: "It is a famous city on the coast of the Indian Sea, towards the Yemen, and it is poor, with no water or pasture. They drink from a spring between it and Aden, about a distance of about today, and despite that, it is bad, except that this place is the port for Indian ships, and merchants gather there for that reason, as it is a town of trade." And it is added to Abyan, which is the opposite of Aden in its entirety.
Ibn Manzur said: "It is a country on the edge of the sea in the furthest part of Yemen."
Ibn Khaldun said: "This Aden is one of the most fortified cities in Yemen, and it is on the bank of the Indian Sea. It is still a country of trade from the time of the Trabaids, and most of them were built with stones, which is why silk merchants visit it often."
Aden is an ancient port and was mentioned by the Greeks under the name (Ancient Greek: Αραβία Εμπόριον, romanised: Arabia Emporion), which means an Arabic trade port. The port's convenient position on the sea route between India and Europe has made Aden desirable to rulers who sought to possess it at various times throughout history. Known as Eudaemon (Ancient Greek: Ευδαίμων, meaning "blissful, prosperous") in the 1st century BC, it was a transshipping point for the Red Sea trade, but fell on hard times when new shipping practices by-passed it and made the daring direct crossing to India in the 1st century AD, according to the Periplus of the Erythraean Sea. The same work describes Aden as "a village by the shore", which would well describe the town of Crater while it was still little developed. There is no mention of fortification at this stage. Aden was more an island than a peninsula, as the isthmus (a tombolo) was not then so developed as it is today. Aden was explicitly mentioned by this name in the Book of Ezekiel, which talks about Jerusalem, and it says:"The merchants of Sheba and Raamah are your merchants. They set up your markets with the finest perfumes and every precious stone and gold. Harran, Qena, and Aden are the merchants of Sheba, and Assyria and Kilmud are your merchants."At its beginning, the city was a small peninsula with no significant natural resources, but its location between Egypt and India made it important in the ancient Indian Ocean trade route. The city was the home of the ancient Kingdom of Awsan from the eighth to seventh centuries BC. In the beginning of the seventh century BC, Karibʾil Watar I, king of the Kingdom of Sheba, launched a campaign against Awsan during which, according to the Sabaean texts, sixteen thousand people were killed, forty thousand people were enslaved, and the kings of Awsan made offerings to the god Almaqah, according to the inscription that Karibʾil Watar I left in Sirwah, commemorating his victory.
In the second half of the first century BC, the Roman Emperor Augustus Caesar determined to control Arabia Felix and reach the Indian Ocean. Aelius Gallus' Roman expedition to Arabia Felix (26–25 BCE) aimed to capture the Sabaean capital of Marib but failed due to extreme desert conditions, disease, and logistical challenges. After an unsuccessful week-long siege, the army, weakened by illness and dehydration, withdrew, losing most of its ~10,000 troops to environmental factors and disease" The Himyarites overthrew the Kingdom of Sheba in 275 AD and took control of Aden. Recent incomplete archaeological studies suggest that the Himyarites were the ones who built the huge water cisterns currently known as the "Cisterns of Aden", which stored nearly 30 million imperial gallons of water (approximately 130 million litres).
The Himyarite Kingdom fell in the first quarter of the sixth century AD. Yusuf Dhu Nuwas mentioned Bab al-Mandab in one of his writings. The forces of the Kingdom of Aksum were entering Yemen through it. The Byzantine Emperor Justinian I sent a fleet to fight the Himyarite Jews and support the Kingdom of Aksum and the Christians of Najran. The fleet entered through Aden. Byzantine sources indicate that the Sasanian Empire took control of the city in 571 AD.
A local legend in Yemen states that Aden may be as old as human history itself. Some also believe that Cain and Abel are buried somewhere in the city.
Although the pre-Islamic Himyar civilisation was capable of building large structures, there seems to have been little fortification at this stage. Fortifications at Mareb and other places in Yemen and the Hadhramaut make it clear that both the Himyar and the Sabean cultures were well capable of it. Thus, watchtowers, since destroyed, are possible. However, the Arab historians Ibn al Mujawir and Abu Makhramah attribute the first fortification of Aden to Beni Zuree'a. Abu Makhramah has also included a detailed biography of Muhammad Azim Sultan Qamarbandi Naqsh in his work, Tarikh ul-Yemen. The aim seems to have been twofold: to keep hostile forces out and to maintain revenue by controlling the movement of goods, thereby preventing smuggling. In its original form, some of this work was relatively feeble.
With the introduction of Islam to Yemen in the seventh century AD, Aden experienced a period of stagnation that lasted until the ninth century AD. In the early years of Islam, Aden belonged to the province of Jund (Taiz). It was controlled by the state of Ziyadid and the Sulayhid. After the death of Ali bin Muhammad Al-Sulayhi, his son took charge of Zurayids, and Aden continued to pay the annual royalty until Queen Arwa bint Ahmed Al-Sulayhi reduced it. After the fall of the Sulayhid state, the Banu Zurayi became independent in Aden, taking advantage of the Sulayhids' preoccupation with the Khawlan tribes. The Zurayites continued to rule Aden, Lahj, and Abyan for less than forty years until they fell under the Ayyubids' control of the city. A major battle took place between Turan Shah bin Ayyub and Yasser bin Bilal al-Muhammadi, Minister of State, and the Zurayiyyah were defeated and al-Muhammadi fled to Taiz. One of the most important contributors to the defeat of the Zurayids was their ongoing wars with the Bani Mahdi in Tihama and the departure of their army to confront the Ayyubids instead of fortifying themselves in Aden.