The Queen has celebrate the 100th anniversary of the Women's Institute at the organisation's centenary annual meeting this morning.
The monarch, who became a WI member in 1943, will cut a celebratory cake during the event at the Royal Albert Hall.
Watch the Queen's slightly unusual approach to cutting the fruit cake:
She was joined by the Princess Royal and Countess of Wessex.
Since January 1 2014, a specially designed centenary baton has been travelling around the UK throughout the WI's 69 federations in England, Wales and the islands to celebrate the links of friendship and community developed through the organisation.
The Queen, who is the organisation's honorary president, received the baton and watched footage of its journey to the Royal Albert Hall.
Later, Sophie will host a Palace garden party in honour of the centenary of the charity Blind Veterans UK.
A hundred years of the Women's Institute:
The WI was formed in 1915, a year into the First World War to rejuvenate rural communities and encourage women to become more involved in producing food to help combat German naval blockades
It was inspired by an idea from Canada
The Anglesey village of Llanfairpwllgwyngyll - famous for having Britain's longest place name - hosted the first meeting
Traditionally associated with "jam and Jerusalem", the WI has modernised in recent years
Every individual WI meets at least once a month
Meetings usually feature speakers, demonstrations or activities aimed at expanding its members' skillset.
Its most famous members - the Calendar Girls - appeared semi-nude in a fundraising calendar for the organisation
There are currently 212,000 WI members
It is the largest voluntary women's organisation in the UK