The UAE president was welcomed with full ceremonial splendour Tuesday for a two-day state visit to Britain, but he faces questions later over claims of torture from three British men jailed in Dubai.
Sheikh Khalifa bin Zayed al-Nahayan, head of state of the United Arab Emirates, is being hosted by Queen Elizabeth II at Windsor Castle, west of London, in a visit aimed at boosting relations between the two countries.
Tuesday's programme focused on meetings between royalty, with the queen hosting a state luncheon at which both heads of state made speeches.
But on Wednesday the president will meet Prime Minister David Cameron for talks, when the premier was to raise the case of three British men who claim they were tortured by Dubai police after being arrested on drugs charges.
At the start of the visit, Sheikh Khalifa sat alongside the queen for a carriage procession through Windsor to the castle, thought to be her favourite residence and where she spends most of her weekends.
They were escorted by the Household Cavalry, wearing breastplates and plumed helmets, while guardsmen from the 1st Battalion Welsh Guards in their scarlet tunics and bearskins formed a guard of honour.
"Our two countries have been close friends since before the foundation of the United Arab Emirates in 1971," Queen Elizabeth said at the luncheon.
Among the guests was the UAE's deputy prime minister, Sheikh Mansour bin Zayed al Nahayan, owner of English Premier League football club Manchester City.
The queen added: "The UAE is one of our largest trading partners in the Gulf region, and we have welcomed Emirati investments in the United Kingdom in many areas from the construction of the largest port facilities in the UK to the Emirates Skyline -- the spectacular cable-car crossing over the Thames -- and, of course, Manchester City."
Sheikh Khalifa was sat between Queen Elizabeth and Cameron at the luncheon.
The president said in his speech: "We shall strive to develop further the long-established bilateral relations that exist between the UAE and the UK in all fields."
He added that he hoped the visit would "reinforce our deep-rooted and steadfast friendship".
After lunch, Queen Elizabeth gave Sheikh Khalifa a falcon head statuette, while he gave her a five-strand pearl necklace made from natural Gulf pearls and a gold-framed family photograph.
Cameron's spokesman said nothing was off-limits for the talks on Wednesday, when asked if he would discuss the claims that the three men were beaten and given electric shocks after being arrested.
"Clearly we have a state visit, we have an opportunity to build and strengthen relations between our two countries and as part of that we'll be talking about a wide range of issues which will include concern about these cases," he said.
"The prime minister's clear there's no no-go areas in this.
"We've asked for a full impartial and independent investigation into the incidents."
Authorities in the UAE have dismissed the allegations, saying an internal investigation found them to be "baseless".