Saudi Arabia, the UAE, Bahrain, Egypt and Yemen on Monday cut ties with Qatar, a small Gulf state which burst onto the diplomatic scene thanks to its rich energy resources.
Here are key facts about the tiny kingdom, now facing what is potentially its worst diplomatic crisis.
History and politics
Qatar is one of the smallest Arab states with a population of 2.4 million, 90 percent of whom are foreigners, and a total area of 11,437 square kilometres (4,415 square miles).
The country was a British protectorate for 55 years until 1971, when it refused to join the United Arab Emirates and emerged as an independent kingdom.
Qatar has been ruled by a monarchy, the Al-Thani family, since the mid-19th century.
The current emir, Sheikh Tamim bin Hamad Al-Thani, rose to power in 2013 after his father Sheikh Hamad bin Khalifa Al-Thani abdicated the throne.
Qatar's constitution has been in place since 2005. The constitution does not authorise political parties.
An as yet unimplemented article in its constitution stipulates that two-thirds of the country's 45-seat consultative council be elected by popular vote.
Economy and investments
Gas-rich Qatar has an annual per capita income of $138,480 (123,098 euros), one of the highest in the world, according to the World Bank.
The kingdom since last year has posted a budget deficit, as the state adapts to lower hydrocarbon prices.
Qatar's economy is now projected to grow at a slower pace and it posted 2.7 percent growth in 2016, down from 4.4 percent three years ago.
A member of OPEC, Qatar is the number one producer and exporter of liquefied natural gas and holds the world's third-largest reserves.
It is also a prime investor in international stocks, with a 17 percent share in Volkswagen and 10 percent of the Empire State Building.
Qatar has invested nearly 40 billion pounds sterling ($51 billion, 46 billion euros) in the UK in recent years, including the purchase of high-end retailer Harrods and Sainsbury, the country's second-largest supermarket chain.
The state owns France's Paris Saint-Germain football club and sports channel beIN, a subsidiary of Al-Jazeera satellite television.
It is also the main shareholder of top French media group Lagardere, and Qatari investors own France's Printemps department store.
Qatar is to host the 2022 World Cup and has invested in massive infrastructure construction estimated to top $200 billion (177.9 billion euros) in costs.
The controversial 2010 decision by world football's governing body FIFA to grant Doha the honour sparked corruption investigations by Swiss and US courts.
International rights groups have also raised concern around working conditions for labourers building Qatar's World Cup facilities.
Subscribe to Arabian Business' newsletter to receive the latest breaking news and business stories in Dubai,the UAE and the GCC straight to your inbox.