Qatar has attracted significant controversy over its hosting of the World Cup – but it's not the only time the country has found itself in the spotlight this year.
In June, The Sunday Times reported that King Charles – then a prince – was alleged to have accepted cash donations totalling €3m (nearly £2.6m) for his Prince of Wales Charitable Fund from a former Qatari prime minister.
While the newspaper reported "there is no suggestion the payments were illegal", Charles was said to have received three lots of cash in person from Sheikh Hamad Bin Jassim Bin Jaber Al Thani, Qatar's PM between 2011 and 2005.
On one occasion, the Times said, Sheikh Hamad handed Charles €1m in notes stored inside paper bags from Fortnum & Mason, the London luxury store that has a royal charter, raising "serious questions about the personal judgement" of the new monarch.
Charles was subsequently widely reported to have said that donations of bags of cash going to his charities will "not happen again". A month later, the Charity Commission declined to launch an investigation saying it had "no concerns".
Charles's longstanding relationship with the former Qatari prime minister has been reportedly close, with Sheikh Hamad gifting the British royal a £147,000 horse and reportedly "contributing to the upkeep of one of his castles in Scotland".
The UK and Qatar have a longstanding relationship, with the BBC saying that "at the core" of the UK's relationship with the Gulf state "is gas".
The small state is one of the biggest exporters of liquified natural gas globally, and the second biggest provider to the UK.
However, the links between the two countries go beyond energy.
The ruling family of Qatar and the sovereign wealth fund – the Qatar Investment Authority – own swathes of London, including Harrods, 20% of Heathrow Airport and the Shard.
Elsewhere in its portfolio is 6% of Barclays Bank, 7% of the London Stock Exchange and 15% of Sainsbury's.
In 2018, the late MP Sir David Amess called the state "a valued ally of the United Kingdom", and highlighted the cooperation on defence between the two countries that "contributes significantly to the UK's economy".
But it is the Royal Family that is said to have helped play a major role in maintaining strong relations with the Qatari ruling family.
According to CNN, "much of Britain's traditional control in the region had been rooted in monarchies that had either been imposed or backed by it through close ties to its royal family".
It quoted an academic, Kristian Ulrichson, as saying: "The Royal Family has provided a means for Britain to forge and maintain decades-long connections with ruling elites... in ways that would be difficult for elected political leaders to replicate."
The late Queen Elizabeth shared a good relationship with the House of Al-Thani – Qatar's ruling family – as well as an interest in horse racing.
The Qatar Investments & Projects Development Holding Company (QIPCO) became the first-ever sponsor of Royal Ascot in 2014.
Emir Sheikh Tamim Bin Hamad Al Thani attended the Queen's funeral in September and, according to The Guardian, "his cousin, horse racing enthusiast Hamad Bin Abdullah, was among the even more select group at her committal at Windsor Castle".
The sheikh was also one of the last foreign rulers to visit the Queen in May, in what would be one of her final engagements as her health declined.
Queen Elizabeth visited Qatar in 1979 and in 2010 hosted then-Emir Sheikh Hamad Bin Khalifa Al Thani during a state visit.
In her speech at the state banquet, the Queen called the Qatari people "old and valued friends" and expressed her hope that the UK would be a "home from home" for them.
She also said that "the state of Qatar and the United Kingdom, as well as our two families, have been in close touch with each other for a long time", noting that her "two sons, Charles and Andrew, have come to know Qatar well".
Until 2011, Prince Andrew acted as special representative for trade for the UK, a role he relinquished in July of that year following an increase in criticism of his friendship with convicted sex offender Jeffrey Epstein.
However, despite officially giving up his trade envoy position, Andrew continued to undertake meetings across the globe relating to British trade, with "meetings with 15 ministers from foreign governments in Qatar, Hong Kong and Saudi Arabia" taking place in the six months after relinquishing his role.
Initially, Buckingham Palace defended Andrew continuing this work, as did the government.
Its UK Trade & Investment (UKTI) government department was quoted as saying at the time that Andrew "is particularly valuable in some parts of the world where continuity is valued over continually changing personnel".