Find out what made Kate Middleton laugh hysterically during outing with Prince William – live updates

Prince William and Kate have stepped out in London for their first joint engagement following the Duchess' maternity leave. The couple attended the Global Ministerial Mental Health Summit, which sees political figures, leading academics and policy-makers from around the world come together with one common goal: better mental health for all.

William and Kate are passionate about the issue, having set up Heads Together, their mental health campaign, in 2016. Tuesday's meeting helped countries work together to deal with stigma attached to mental health and address other issues to do with mental ill-health.

It was Kate's second engagement since returning to work following her maternity leave, and she looked excited to be back on the royal circuit, championing issues close to her heart.

See the best photos from their outing here…

The couple viewed the work of Dairo Vargas, a contemporary fine artist from Columbia who was painting an original piece of art at the Summit, inspired by the day's events. Creative Kate, a history of art graduate, lent her skills and had a go at painting a bit of the artwork. 

Her husband William had nominated her as "the arty one". "Where can you hide it?" Kate joked as she painted a white stroke. "It's almost ruined the picture," William teased. "No, this is probably how you ruin a picture," he added, taking his turn.

The Duchess looked lovely in lilac as she arrived at County Hall in London. She recycled her fit and flare dress by Emilia Wickstead, which she wore during her royal tour of Germany in 2017. Kate, 36, accessorised with her favourite nude court shoes and an Aspinal handbag.

She had her trademark brunette hair, which looked like it had had a smattering of copper low lights, in a loose, lightly curled style. The Duchess completed her look with brown eyeshadow, a subtle flick of mascara and nude lipgloss to highlight her pretty features.

A closer look at Kate's pretty lilac outfit.

The couple were greeted by Health Secretary Matt Hancock as they arrived at the first Global Ministerial Mental Health Summit. They were met by cheering crowds, who had gathered in the street to catch a glimpse of the royals.

During the summit, William and Kate attended a workstream on 'Children, Young People and the Next Generation' where they heard presentations on two case studies of active mental health programmes from Slovenia and the US. The workstream reflected one of the six key themes being discussed at the summit. They met young people who have either had or are dealing with mental health issues.

The Duke and Duchess also visited the exhibition area and met with representatives from a number of organisations to hear more about their mental health campaigns and programmes.

Their last stop took William and Kate to a Friendship Bench, part of an innovative programme from Zimbabwe which has taught elderly Zimbabwean women the skills to become city lay health workers.