Mr Bettel refused to move a press conference with the British PM indoors to prevent Mr Johnson being ‘drowned out’ by a noisy anti-Brexit protest.
He then proceeded to address the media on his own as he gestured at the empty podium next to him and delivered a furious anti-Brexit rant.
The way in which Luxembourg treated Mr Johnson sparked widespread criticism in the UK with even the PM’s critics rebuking Mr Bettel.
The PM’s disastrous trip to Luxembourg has thrust the country into the world spotlight. Here’s everything you need to know about it.
A controversial tax haven that saves big business and the mega-rich millions
A major investigation by the International Consortium of Investigative Journalists in 2014 showed that Luxembourg was being used as a tax haven. The scandal became known as ‘Lux Leaks’.
An analysis of almost 28,000 pages of leaked financial documents showed the government of Luxembourg had granted beneficial tax deals to a number of large corporations.
The documents showed more than 300 companies such as Burberry, Heinz, Dyson, Pepsi, IKEA and Deutsche Bank were among those to channel funds through the tiny European nation using complex financial structures.
The deals – which were legal – allowed companies to pay less tax on money they moved to Luxembourg with the transactions also remaining secret.
Jean-Claude Juncker came under fierce scrutiny when the story first broke because he was in charge of the country when many companies were taking advantage of the tax avoidance schemes.
The president of the European Commission earlier this year reportedly described his initial response to the ICIJ investigation as a ‘major mistake’ because he ‘took too much time to respond’ to it.
‘I should have responded immediately,’ Mr Juncker reportedly said in May.
Luxembourg’s economy is less than HALF the size of the NHS budget
Luxembourg’s gross domestic product in 2017 was about £50 billion – a fairly staggering amount given the fact the country has a population of approximately 600,000.
So while it is only the 164th biggest country by population, it is well inside the top 100 countries in the world when it comes to the size of its economy.
However, its economy represents less than half of the budget of the NHS. Total health spending in the UK stood at approximately £129 billion in 2018/19.
In contrast, the United Kingdom’s gross domestic product in 2017 was more than £2 trillion.
That puts the UK inside the top 10 economies in the world. The UK’s population of just over 67 million people puts Britain in the top 30 countries by population size.
Its most famous export is… Jean-Claude Juncker
Mr Juncker was elevated to the world stage in 2014 when he was installed as the president of the European Commission.
Before that he was the prime minister of Luxembourg from 1995 to 2013 – an 18 year term which made him the longest serving head of any national government in the EU.
His time as the top bureaucrat in Brussels has been anything but straight forward and he has shown something of a penchant for putting himself at the centre of political firestorms.
In 2015 he sparked controversy when he welcomed Hungarian leader Viktor Orban to Brussels by saying ‘the dictator is coming’ before shaking hands with a cheeky smile.
Boris Johnson went to Luxembourg yesterday for talks with Jean-Claude Juncker but his trip was largely overshadowed by a bizarre press conference conducted by Xavier Bettel
Mr Johnson declined to take part in the press conference after Mr Bettel, Luxembourg’s PM, refused to move it despite there being an anti-Brexit protest nearby
In August 2016, as the EU wrestled with Europe’s refugee crisis, Mr Juncker remarked: ‘Borders are the worst invention ever made by politicians.’
In December 2018 he was confronted by Theresa May at a European Council summit after he appeared to call the UK PM’s Brexit plan ‘nebulous’. Mr Juncker was forced to beat a hasty retreat as he pleaded his innocence in front of a visibly angry Mrs May.
He was also rebuked at the same summit after he greeted a female colleague by ruffling her long blonde hair.
Meanwhile, footage of Mr Juncker struggling to walk in July last year at a Nato summit prompted questions about his health.
The European Commission responded with fury to suggestions Mr Juncker may have been drunk as a spokesman said it was down to a ‘particularly painful attack of sciatica’.
It was not the first time Mr Juncker appeared to be unsteady on his feet in public and Mr Juncker himself has previously blamed sciatica.
Luxembourg’s Prime Minister is Xavier Bettel, the fiercely anti-Brexit son of a wine merchant who humiliated Boris in front of jeering Remainer crowds
Mr Bettel has been the prime minister of Luxembourg since 2013 but he is almost completely unknown on the international stage.
He has been a vocal critic of Brexit and the amount of time it has taken the UK to set out the terms on which it wants to leave the EU.
Speaking in the run up to the original March 2019 Brexit deadline, he said: ‘We don’t force the United Kingdom, you decided to leave, we shouldn’t exchange roles.
‘You want us to be the bad guy. You decided. You decided. You decided.
‘We have to just find a deal and we negotiated the deal, we found the best possible deal and we are not in a souk where we are going to bargain for the next five years.’
The 46-year-old is married and in 2018 he became the first openly gay PM in the world to be re-elected for a second term in office.
He previously served as the Mayor of Luxembourg City between November 2011 and December 2013.
Mr Bettel greeted Mr Johnson ahead of their meeting at the prime minister’s office in Luxembourg yesterday
Mr Bettel and Mr Johnson’s meeting appeared to be cordial enough but the Luxembourg PM seemed much happier today in Paris as he was given a pat on the back by Emmanuel Macron as they met for talks
He then led the Democratic Party into Luxembourg’s national elections in 2013, finishing third.
However, he was invited to form the next government and became PM, leading a coalition of the Democratic Party, Luxembourg Socialist Workers’ Party and The Greens.
The government remained a rainbow coalition after elections last year.
He is reportedly the son of a wine merchant and a distant relation of the Russian composer Sergei Rachmaninoff.
He studied at university in France before also spending time at Aristotle University in Greece.
It was ‘saved’ from Nazi ‘Germanisation’ by the Allies in the Second World War
Mr Bettel’s actions at the press conference yesterday prompted a furious backlash from Tory Brexiteers as former Cabinet minister Iain Duncan Smith pointed out the UK had ‘saved’ the country from the Nazis during the Second World War.
Mr Duncan Smith said world leaders had a duty to show ‘courtesy and civility’ as he suggested Luxembourg had more reason than most to be courteous to Britain.
He told The Telegraph: ‘The irony is that Luxembourg was saved by Britain. National leaders should always treat one another with courtesy and civility. Good ones do.’
Luxembourg was invaded by Nazi Germany in May 1940 even though it was officially designated as neutral country, with Britain playing a key role in its liberation.
Initially after it was invaded it was put under the control of a military administration before it was eventually annexed and made a formal part of Germany.
The Nazis tried to portray Luxembourg as a natural part of the Third Reich and used propaganda and terror to try to ‘Germanise’ the population.
The ‘Germanisation’ of Luxembourg involved trying to get rid of all French influence over the country and the Nazis banned the French language and made German the official language. Wearing a beret was also outlawed.
Luxembourg was liberated by the Allies in September 1944 but while the capital city remained in their control they had to fight off a major counter offensive from the Nazis in the December and beyond.
The Nazis launched what would be their final major attack of the war at the end of 1944 as they tried to push through the heavily-forested Ardennes region, spanning parts of Belgium, France and Luxembourg – in order to stop the Allied advance.
The ensuing clash became known as the Battle of the Bulge as German units initially made big gains, causing a ‘bulge’ in the Allied defensive line.
The battle lasted just over a month as both sides suffered heavy losses before the Allies prevailed at the end of January 1945.
The man put in charge of Luxembourg by the Nazis, Gustav Simon, was captured after the war had ended and was taken to a British Army prison in central Germany where he is believed to have committed suicide in December 1945.
Simon was the party leader of a regional branch of the Nazi Party and was made the chief of the civil administration in Luxembourg during the occupation. He was appointed to the role by a decree made by Adolf Hitler himself.
It is heavily reliant on banking to prop up its economy
Perhaps unsurprisingly given the size of its economy versus the size of its population, the Luxembourg economy is largely dominated by financial services.
The Global Financial Centres Index ranks Luxembourg as the 30th most competitive financial services area in the world.
In Europe it is only behind London, Frankfurt, Paris, and Geneva.
Beyond banking, Luxembourg is an export-heavy economy with Germany, France and Belgium its biggest export partners.
Machinery, computers, iron and steel are among the country’s main exports.
It is officially called the Grand Duchy of Luxembourg
Luxembourg is the only grand duchy remaining in the world – a term which is given to a country or area which has a grand duke or grand duchess as its official head of state.
The current monarch is Henri, the Grand Duke of Luxembourg, who has reigned since October 2000.
His constitutional role is largely ceremonial.
It is the home of the European Court of Justice
Despite it’s small size, Luxembourg plays a key role in the EU as the home of the European Court of Justice.
It is based in Luxembourg City itself and is the EU’s top court, having the final say on all matters of European law.
Luxembourg City is home to the European Court of Justice. As the EU’s highest court it is the subject of intense hatred for many Brexiteers
As a result it has been repeatedly attacked by Brexiteers who view it as everything that is wrong with being a member of the EU – namely that Britain must abide by laws and judgements made far away from Westminster.
Leaving the jurisdiction of the ECJ is frequently cited by Brexiteers as one of the keys to Britain regaining its sovereignty.
The court added to Eurosceptic fury in December last year after it ruled that the UK can cancel Brexit without the permission of the other 27 EU member states.