After the August Revolution and the fall of the Nguyễn dynasty, the Democratic Republic of Vietnam (DRV) designated Hanoi as the capital of the newly independent country.

A square adjacent to the Hoàn Kiếm lake was named Đông Kinh Nghĩa Thục after the reformist Tonkin Free School under French colonization.

[14][18][21] Arab manuscripts between the 9th and 12th century referred to Hanoi as Luqin (لوكين), a term derived from Longbian (Middle Chinese: Ljowng-pen), and was originally used by Muslim traders to mention the Vietnamese.

Between 1971 and 1972, archaeologists in Ba Vì and Đông Anh discovered pebbles with traces of carving and processing by human hands that are relics of Sơn Vi Culture, dating from 10,000 to 20,000 years ago.

[28] During the mid-Holocene transgression, the sea level rose and immersed low-lying areas; geological data clearly show the coastline was inundated and was located near present-day Hanoi, as is apparent from the absence of Neolithic sites across most of the Bac Bo region.

[30][31] In around third century BC, An Dương Vương established the capital of Âu Lạc north of present-day Hanoi, where a fortified citadel is constructed, known to history as Cổ Loa,[32] the first political center of the Vietnamese civilization pre-Sinitic era,[33] with an outer embankment covering 600 hectares.

[38][39] Han dynasty organized Nanyue into seven commanderies of the south (Lingnan) and now included three in Vietnam alone: Giao Chỉ and Cửu Chân, and a newly established Nhật Nam.

[42][44][45] It began at the Red River Delta, but quickly spread both south and north from Jiaozhi, stirring up all three Lạc Việt regions and most of Lingnan,[45][43] gaining the support of about 65 towns and settlements.

[46][47] In 42 AD, the Han emperor commissioned general Ma Yuan to suppress the uprising with 32,000 men, including 20,000 regulars and 12,000 regional auxiliaries.

[48] By the middle of the fifth century, in the center of ancient Hanoi, a fortified settlement was founded by the Chinese Liu Song dynasty as the seat of a new district called Tống Bình (Songping) within Giao Chỉ commandery.

[52] In the latter half of the eighth century, Zhang Boyi, a viceroy from the Tang dynasty, built Luocheng (Chinese: 羅城; Vietnamese: La Thành) to suppress popular uprisings.

[55] Đại La at the time had approximately 25,000 residents, including small foreign communities of Persians, Arabs, Indian, Cham, Javanese, and Nestorian Christians.

After the Đổi Mới economic policies were approved in 1986, the Communist Party and national and municipal governments hoped to attract international investments for urban development projects in Hanoi.

Public outcry in opposition to the redevelopment of culturally significant areas in Hanoi persuaded the national government to implement a low-rise policy surrounding Hoàn Kiếm Lake.

In general, the terrain becomes gradually lower from north to south and from west to east, with the average height ranging from 5 to 20 meters above sea level.

Spring, from March until the end of April, Hanoi is usually characterized with large amounts of drizzle and little sunshine due to the strong activity of the southeast monsoon blowing moisture from the sea inland.

Nowadays, the city is both a major metropolitan area of Northern Vietnam, and also the country's cultural and political centre, putting a lot of pressure on the infrastructure, some of which is antiquated and dates back to the early 20th century.

Even in the Old Quarter, where commerce started hundreds of years ago and consisted mostly of family businesses, many of the street-front stores nowadays are owned by merchants and retailers from other provinces.

There are more than 50 ethnic groups in Hanoi, of which the Viet (Kinh) is the largest; according to official Vietnamese figures (2019 census), accounting for 98.66% of the population, followed by Mường at 0.77% and Tày at 0.24%.

Agriculture, previously a pillar in Hanoi's economy, has striven to reform itself, introducing new high-yield plant varieties and livestock, and applying modern farming techniques.

[96] Many foreigners believe that the vendors add a traditional and nostalgic aura to the city, although street vending was much less common prior to the 1986 Đổi Mới policies.

[110] The area is famous for its specializations in trades such as traditional medicine and local handicrafts, including silk shops, bamboo carpenters, and tin smiths.

The Franco-Chinese or hybrid architectural styles can be reflected in the front of a house in the co-existence of French-styled columns, Confucian scrolls, the Taoist yin-yang sign, and the Buddhist lotus sculpture.

The lakeside road in the Nghi Tam – Quang Ba area is perfect for bicycling, jogging and viewing the cityscape or enjoying the lotus ponds in the summer.

Modern and traditional theaters, cinemas, karaoke bars, dance clubs, bowling alleys, and an abundance of opportunities for shopping provide leisure activity for both locals and tourists.

Nhà Triển Lãm at 29 Hang Bai street hosts regular photo, sculpture, and paint exhibitions in conjuncture with local artists and travelling international expositions.

Bún chả, a dish consisting of charcoal roasted pork served in a sweet/salty soup with rice noodle vermicelli and lettuce, is by far the most popular food item among locals.

American President Barack Obama famously tried this dish at a Le Van Huu eatery with Anthony Bourdain in 2016, prompting the opening of a bún chả restaurant bearing his name in the Old Quarter.

Such events usually take place in June and July, during which a large number of students and their families converge on the city for several weeks around the intense examination periods.

[130] The Reunification Express between Hanoi and Ho Chi Minh City covers a distance of 1,726 km (1,072 mi) and takes approximately 33 hours.