Article continues below advertisementPrince George will be hitting a big milestone next summer: celebrating his 13th birthday.The 12-year-old royal is set to attend secondary school in September 2026 - and he may even go to Prince William's alma mater, Eton College.Article continues below advertisementSource: MEGAPrince George is set to enter secondary school next year.George currently attends Lambrook School with his younger siblings, Princess Charlotte and Prince Louis.