[5] In 1918, the Chinese government, under the control of the warlord Duan Qirui, secretly agreed to Japanese terms in exchange for a loan.

Following the First World War, during the Paris Peace Conference, Japan secured agreements with the Allied powers to recognize its claim to the areas in Shandong, which included Qingdao, previously occupied by Germany.

[3] Today, Qingdao is a major nodal city of the Belt and Road Initiative (BRI) that connects Continental and East Asia with Europe.

As of the 2020 census, Qingdao built-up (or metro) area made of the seven urban districts (Shinan, Shibei, Huangdao, Laoshan, Licang, Chengyang and Jimo) was home to 7,172,451 inhabitants, making it the 15th largest city in China by population.

[8] Lying across the Shandong Peninsula and looking out to the Yellow Sea, it borders the prefecture-level cities of Yantai to the northeast, Weifang[9] to the west and Rizhao to the southwest.

[23] In 1891, the Qing Empire decided to make coastal Qingdao (then known as "Jiao'ao") a defense base against naval attacks and began to improve its fortifications.

[24] The preindustrial, waning Qing Empire was forced to concede the area to Germany the following year, and the Kiautschou Bay concession, as it became known, existed from 1898 to 1914 (Li 2005, p. 81).

Jiaozhou was alternatively romanized as Kiaochow, Kiauchau, or Kiao-Chau in English, and Kiautschou in German; Qingdao was its administrative center.

The growing Imperial German Navy based their East Asia Squadron there, allowing the warships to conduct operations throughout the western Pacific.

[28] Before the outbreak of World War I (1914–1918), ships of the German naval forces under Admiral Count von Spee were located at central Pacific colonies on routine missions.

[note 1] After a minor British naval attack on the German concession in Shandong in 1914, Japanese Empire troops occupied the city and the surrounding province during the Siege of Tsingtao (Qingdao) after Japan's declaration of war on Germany in accordance with the Anglo-Japanese Alliance.

[30] The decision of the Paris Peace Conference and the Versailles Treaty negotiations not to restore Chinese rule over the previous foreign concessions in Qingdao after the Great War triggered the May Fourth Movement (4 May 1919) of anti-imperialism, nationalism and cultural identity in China.

On 2 June 1949, during the Chinese Civil War and shortly before the founding of the communist People's Republic of China on 1 October 1949 the city was taken by Chairman Mao Zedong and his troops.

Sun Yat-sen (1866–1925), leader of the Chinese Revolution of 1911 and subsequently first president of the Republic of China, visited the Tsingtao area and stated in 1912, "I am impressed.

With the development of industry and commerce, a "New City District" was established to furnish the Japanese colonists with commercial sections and living quarters, which suggested a striking contrast to the shabby houses in the local Chinese zones (Li 2007, p. 133).

Since the 1984 inauguration of China's open-door policy to foreign trade and investment, Qingdao has rapidly developed into an ultramodern port city.

Outside of the center of the city, there is a large industrial zone, which includes chemical processing, rubber, and heavy manufacturing, in addition to a growing high-tech area.

Due to the direct regulation of the marine environment, the city is influenced by the southeast monsoon and the currents and water masses from the ocean, so it also has significant maritime climate characteristics.

The decomposing algae release large amounts of hydrogen sulfide gas, which produces an offensive "rotten egg" odor.

Sea lettuce blooms, which are partially caused by seaweed farming in Jiangsu Province, led local officials to declare a "large-scale algae disaster" in 2013.

Living standards are among the highest of leading Chinese cities due to the strong export economy and relatively high family wages.

[citation needed] Qingdao has a zigzagging pattern coastline, and thus possesses an invaluable stock of fish, shrimp, and other sea resources.

[72] Domestic rail lines connect Qingdao with many cities in China, including Beijing, Lanzhou, Chengdu, Xi'an, Zhengzhou, Jinan and Jining.

Non air-conditioned buses cost 1 yuan (excluding the tunnel bus), The volume of road passenger transport approaches 737 million per year.

In the long term, the city plans to build eight subway lines in downtown and some suburban districts, which account for 231.5 km (143.8 mi) in future.

There are a large number of German-style buildings in Qingdao's city center, a remarkable fact considering the German leased-territory period only lasted 16 years (1898–1914).

A local accent known as Qingdao dialect (Chinese: 青岛话; pinyin: Qīngdǎo huà) distinguishes the residents of the city from those of the surrounding Shandong province.

[76] German papers included Deutsch-Asiatische Warte (traditional Chinese: 泰東古今鑑; simplified Chinese: 泰东古今鉴; pinyin: Tàidōng Gǔjīn Jiàn;[77] weekly newspaper published until 1906, included Die Welt des Ostens, Altes und Neues aus Asiens drei Kaiserreichen, a cultural supplement),[76] the Tsingtauer Neueste Nachrichten and the Kiautschou Post (a daily paper published from 1908 to 1912, referring to the Kiautschou (Jiaozhou) Bay concession).

These events were hosted at the Qingdao International Sailing Centre and held in Fushan Bay, near the city's central business district.

5The claimed province of Taiwan no longer have any internal division announced by Ministry of Civil Affairs of PRC, due to lack of actual jurisdiction.