President Bashar Al-Assad of Syria and his British-born wife Asma meet the Queen at Buckingham Palace in December 2002. Photo / Getty Images
Tyrants, former enemies and leaders accused of human rights abuse have all enjoyed state visits, reports Daily Mail.
Controversial guests include:
He and British-born wife Asma dined with the Queen at Buckingham Palace in December 2002.
The visit was mired in controversy due to his alleged support of Palestinian and Islamic terror groups.
Assad now stands accused of killing civilians with chemical weapons and barrel bombs during Syria's civil war.
Protesters turned out in force for his visit in October 2015 – and there were even rumours of royal unrest.
Amnesty International, pro-Tibet campaigners and followers of the Falun Gong spiritual practice, banned in China, were present on The Mall in central London.
The Russian president's only state visit in June 2003 was marked by protests against his repression of separatists in Chechnya.
The visit, organised by Tony Blair, who admired Putin as a "moderniser", took place three years before the murder of Russian dissident Alexander Litvinenko in London, allegedly by Russian agents, which hardened relations with Moscow.
The then-president was blamed for the massacre of 10,000 people in the 1980s, long before his visit to Britain in May 1994.
But, with the full horror yet to emerge, he was welcomed as a trading partner and for his "influence on peace" in Africa.
He was greeted by Princess Margaret at Heathrow and taken by Rolls Royce to meet the Queen and then-PM John Major.
He accompanied the monarch for a five-minute procession by carriage to Buckingham Palace.
Mugabe was made an honorary KCB during the visit. He was later stripped of the honour.
His regime was blamed for up to a million deaths after the invasion of East Timor, four years before his UK visit in November 1979.
But the despot's arrival was hailed by some as an "excellent opportunity" for the UK defence industry. He was confronted in Downing Street by protesters.
Dissidents from Romania who had fled the Communist regime were outraged at his visit in June 1978.
Jim Callaghan's Labour government wanted to broker a deal with Romania to co-produce aeroplanes.
Shortly before their arrival, French president Valery Giscard d'Estaing telephoned the Queen to warn that Ceausescu and his wife Elena had walked off with valuables from their state rooms on a visit to Paris.
The dictator, who visited in December 1973, presided over the collapse of his country's economy and locked up dissidents.
He was later found to have embezzled £12 billion ($17 billion NZD), and was blamed for the deaths of 230,000 people.
Matt Gaetz accused of violating House rules, denies wrongdoing.