The Queen meets Boris Johnson as Theresa May steps down as Prime Minister – best photos

Wednesday marked Theresa May's last day as Prime Minister, and following a farewell lunch at Downing street, she gave a passionate leaving speech, with her husband Philip May standing by her side. Shortly afterwards, Theresa and Philip headed to Buckingham Palace to formally resign. She then met with the Queen – the head of state – where she advised her on who she believed should take over her role – Boris Johnson. 

MORE: How the Queen stays cool in the heatwave

Shortly afterwards, Boris arrived at Buckingham Palace for a private meeting with the Queen - who appointed him as the new Prime Minister of the UK. An official photograph of the pair during their meeting was released by the palace soon afterwards. Boris is the 14th Prime Minister to be appointed in the Queen's reign.

Boris gave a lengthy speech as the new official Prime Minister, where he touched upon his promises - which included better health care and access to great education - along with his proposals for Brexit. He promised to leave the European Union by 31 October, and told the crowds that as the new Prime Minister, his job was to serve everyone. 

Take a look at the photos from this historic day, from Theresa May resigning to Boris Johnson taking over as Prime Minister...

Make sure you never miss a ROYAL story! Sign up to our newsletter to get all of our celebrity, royal and lifestyle news delivered directly to your inbox.

Theresa May gave a speech outside Downing Street on her final day as Prime Minister. 

Theresa said in her departing speech: "I am about to go to Buckingham Palace to tender my resignation to Her Majesty the Queen and to advise her to ask Boris Johnson to form a new administration. I repeat my warm congratulations to Boris on winning the Conservative leadership election." 

She continued: "Of course, much remains to be done – the immediate priority being to complete our exit from the European Union in a way that works for the whole United Kingdom."

Theresa was accompanied by her husband Philip on the historical day, as they waved outside Number 10. 

Crowds gathered outside 10 Downing street as Theresa gave her speech on her final day as the Prime Minister.

Theresa then arrived at Buckingham Palace to resign from her role as Prime Minister. 

Boris Johnson arrived at Buckingham Palace on Tuesday afternoon to meet the Queen and to officially be appointed the role as Prime Minister. 

Buckingham Palace released the official photo of Boris Johnson being appointed the new Prime Minister by the Queen. 

Boris Johnson's girlfriend Carrie Symonds was in the front of the crowd outside Buckingham Palace, waiting to congratulate the new Prime Minister. 

On his first day as Prime Minister, Boris gave his first speech outside 10 Downing street, where he told the crowds that he was there to serve the public, saying: "Do not underestimate this country."

In his speech, Boris spoke of his Brexit promise, telling everyone: "We are going to come out of the EU on October 31st with no ifs or no buts, and we will do a new deal, to develop a new and exciting partnership with the EU. I have every confidence that in 99 days times we will have cracked it."

He added: "The time has come to act, to take decisions, to give strong leadership and to change this country fot he better. The Queen has just honoured me with the extraordinary office of state, and my job is here to honour you, the people."