US first lady Michelle Obama has touched down in the UK for a two-day trip to promote her charity work.
Mrs Obama was greeted by US military families as she stepped off the plane at Stansted Airport this evening, followed by her mother and two daughters.
She is visiting Britain to discuss her campaigns for girls' education and better support for military families.
Tomorrow Mrs Obama is due to meet Prince Harry and have tea at Downing Street with David and Samantha Cameron.
She will also host an event at the Mulberry School for Girls in Tower Hamlets in East London to discuss joint work between America and Britain to boost education for adolescent girls across the world through the Let Girls Learn initiative, championed by her and US president Barack Obama.
Pupils at the single-sex comprehensive will get the chance to grill the first lady - along with former prime minister of Australia Julia Gillard, who chairs the board of the Global Partnership for Education.
The White House said Harry was hosting Mrs Obama two years after attending a mother's day tea for military mothers with her in the US.
Her chief of staff Tina Tchen said: "He was wonderful and it was wonderful to have him here. And we hear from his staff that he is happy to return the favour."
Ms Tchen added that they would be able to talk about "that shared interest that they have on military families".
The Joining Forces campaign - another of those spearheaded by the first lady - "works hand in hand with the public and private sectors to ensure that service members, veterans and their families have the tools they need to succeed throughout their lives".
After London, the party will fly on to Italy to meet US armed services families based in Europe and to visit the Milan Expo as part of the third strand of her work, encouraging healthier diets for children.