Princess Charlotte is "very excited" about starting school, the Duke of Cambridge said as he dropped her off for her first day.
Walking across the playground with both parents and her brother, Princess Charlotte smiled as she met the head of the lower school at Thomas's Battersea.
Prince George has attended the private school in south west London since 2017.
He began his first day of year two - his final year in the lower school before he moves to the middle school.
Ms Haslem bent down to shake hands with both George and Charlotte, who is fourth in line to throne.
The duke and duchess accompanied Charlotte to her classroom before saying their goodbyes.