Prime Minister Theresa May joined the Queen in welcoming the President of Colombia, Juan Manuel Santos for his first ever state visit to the UK on Tuesday (1 November).

Accompanied by his wife, Maria Clemencia Rodriguez de Santos, the president was given a formal welcome at the Royal Pavilion on Horse Guards Parade in London, by Her Majesty, 90, and Prince Philip, Duke of Edinburgh, 95.

The Colombian President was also warmly greeted by PM Theresa May along with Foreign Secretary Boris Johnson and Home Secretary Amber Rudd during the ceremonial procession on the foggy London morning. The UK visit comes hot on the heels after Santos' earned a Nobel Peace Prize for his efforts to end Colombia's long-running civil war.

Ahead of the procession at Horse Guards Parade, known as Henry VIII's former jousting yard, PM May was pictured curtseying as she shook the Queen's hand while dressed smartly in a bouclé Tweed jacket, skirt, hat and statement pearls.

The Queen – dressed in an eye-catching apple-green cashmere coat and silk crepe dress by Angela Kelly – appeared to greet the Colombian president with warmth as he smiled jovially throughout the memorable event.

Juan Manuel Santos
Queen Elizabeth II takes part in a ceremonial welcome for Colombia's President Juan Manuel Santos and his wife Maria Clemencia de Santos at Horse Guards Parade in London Gareth Fuller/ Getty Images
Juan Manuel Santos
Queen Elizabeth II takes part in a ceremonial welcome for Colombia's President Juan Manuel Santos and his wife Maria Clemencia de Santos at Horse Guards Parade in London Gareth Fuller/ Getty Images
Juan Manuel Santos
Queen Elizabeth II greets Colombia's President Juan Manuel Santos at a ceremonial welcome for Colombia's President Juan Manuel Santos and his wife Maria Clemencia de Santos at Horse Guards Parade in London Stefan Wermuth/ Getty Images

Santos and his wife arrived by car after being greeted beforehand by Prince Charles and Camilla, Duchess of Cornwall – who visited Colombia in 2014. The Queen, Prince Philip and other high profile figures along with military top brass stood waiting to officially welcome the visitors.

While in the UK, Mr and Mrs Santos are staying with the Queen at Buckingham Palace in London. They will be entertained at a lavish state banquet this evening.

Juan Manuel Santos
Colombia's President Juan Manuel Santos inspects an honour guard during his ceremonial welcome at Horse Guards Parade, London Stefan Wermuth/ Getty Images
Juan Manuel Santos
Colombia's President Juan Manuel Santos inspects an honour guard with Prince Philip, Duke of Edinburgh during his ceremonial welcome at Horse Guards Parade, London Stefan Wermuth/ Getty Images
Juan Manuel Santos
British Prime Minister Theresa May and Foreign Secretary Boris Johnson arrive to take part in a ceremonial welcome for Colombia's President Juan Manuel Santos and his wife Maria Clemencia de Santos at Horse Guards Parade in London Gareth Fuller/ Getty Images

The Duke of Edinburgh – dressed in a warm navy overcoat, shirt and tie – led the visiting foreign head of state to inspect the Guard of Honour, walking a few steps behind Santos who steamed ahead past the lines of troops in their grey greatcoats and famous bearskins.

Once the welcome ceremony ended, the Queen and her guests departed in a carriage procession for Buckingham Palace.

Though it is the first time a Colombia president has carried out a state visit to the UK, the South American leader and his wife have met Her Majesty once before during a private audience in 2011.

The visit to the UK will see the president view an exhibition in Buckingham Palace's Picture Gallery of items from the Royal Collection relating to Colombia, and he will visit Westminster Abbey and the Palace of Westminster before joining Prince Charles and Camilla, Duchess of Cornwall for tea at Clarence House.

Juan Manuel Santos
British Foreign Secretary Boris Johnson attends the ceremonial welcome at the start of the three-day state visit of Colombian President Juan Manuel Santos at Horse Guards Parade in central London Gareth Fuller/ Getty Images
Juan Manuel Santos
Queen Elizabeth II and Colombia's President Juan Manuel Santos arrive at Buckingham Palace in London Leon Neal/ Getty Images
Juan Manuel Santos
(L-R) Britain's Prince Philip, Duke of Edinburgh, Colombia's first lady Maria Clemencia de Santos, Britain's Queen Elizabeth II and Colombia's President Juan Manuel Santos pose on arrival at Buckingham Palace Leon Neal/ Getty Images

The British capital will mark Mr and Mrs Santos' visit by lighting up the London Eye in yellow, blue and red colours – symbolising the Colombian flag – tonight and tomorrow. A 41-round gun salute was also fired at the Tower of London at midday today.

PM May will then host the President at 10 Downing Street for a working lunch tomorrow. Santos will also attend events at Mansion House, the Natural History Museum and the London School of Economics, while Boris Johnson will treat the president to a private tour of the Cabinet War Rooms.

The foreign secretary addressed Brexit upon welcoming the President. He said: "We have an important national interest in the security and prosperity of Colombia, and we look forward to forging new links in science, education and research, while reinforcing the traditional friendship between our two peoples through increased tourism.

Juan Manuel Santos
Guardsmen prepare to take part in a ceremonial welcome at Horse Guards Parade for Colombia's President Juan Manuel Santos and his wife Maria Clemencia de Santos in central London Stefan Wermuth/ AFP

"Colombia is on the verge of a historic peace agreement and through our ongoing support for the country the UK is well-placed to take advantage of the opportunities that will follow. We will continue to support President Santos and the people of Colombia as they work to secure lasting peace.

"As we leave the EU, Britain remains a bold and outward-looking nation, and we are forging a new global role and taking advantage of economic and diplomatic opportunities in the wider world, beyond Europe.

Juan Manuel Santos
Guardsmen prepare to take part in a ceremonial welcome at Horse Guards Parade for Colombia's President Juan Manuel Santos and his wife Maria Clemencia de Santos in central London Stefan Wermuth/ AFP

"Colombia holds huge potential for British investors in areas ranging from health care to transport, defence and energy, and I hope that the state visit will help to open up these opportunities," he added.

Following his UK visit, President Santos will head to Belfast, Northern Ireland, on Thursday to hear about their experience of peace-building and creating a stronger economy.