A school will launch a ‘happy day’ to celebrate a student’s success.

Queenswood School, in Brookmans Park, will host the event on Wednesday after its pupil Hanni Blaskey’s book What Makes Me Happy? went to number one in Sainsbury’s paperback chart last month.

Hanni, 13, published the book for BBC Children in Need. It features more than 100 celebrities and politicians discussing the things that make them happy.

Pupils and staff at the school will contribute their own messages about happiness to a giant display at the school, and messages will be sent to linked schools around the world, including in Malawi, Japan and Australia.

Hanni will also sign copies of her book at lunchtime.