It is back to business for the glamorous royal couple. Prince William and Kate Middleton officially stepped out for the first time together since the birth of their third child, Prince Louis, back in April. 

The duo headed to the first Global Ministerial Mental Health Summit at London County Hall on Tuesday in London, England. 

The day's agenda included listening in on presentations covering two case studies of active mental health programs from the U.S. and Slovenia. Mental health awareness is something the couple, along with other members of the Royal family, have been actively involved with, having pushed mental health discussions to the forefront. Just last month, Prince William put a spotlight on the importance of mental health in the workplace at a speech he gave in Bristol where he openly disclosed his struggles working as a former air ambulance pilot. 

On the day's outing, the beautiful mother of three looked stunning in a lilac Emilia Wickstead dress, which she paired with dainty jewelry, and matching high heels and bag.