"Prince George will this morning attend his first day of school at Thomas's Battersea, accompanied by his father The Duke of Cambridge," the palace tweeted, alongside a photo of George smiling and wearing a navy blue sweater over a checked, collared shirt. He is holding both hands palm up.
Another tweet featured images of Prince William and George greeted by a woman outside the school, then George walking and holding hands with both William and the woman, while William carries George's schoolbag.
"TRH were met by the Head of Lower School, before The Duke took Prince George inside to his reception classroom," the palace explained in another Twitter post.
William and Kate, who announced this week they are expecting their third child, also have a 2-year-old daughter named Charlotte.
As with her previous two pregnancies, Kate is suffering from hyperemesis gravidarum, which is "very acute morning sickness, which may require supplementary hydration, medication and nutrients," according to the statement.