Cute Pics! Prince George’s First Day of School — Where Was Mom Kate Middleton?

Prince George reached another big milestone in his life — school!

Thursday morning, George, 4, stepped out for his first day of school at Thomas's Battersea in London, accompanied by his dad Prince William.

William told The Sun of his son's first day, "It went well. There was one other parent who had more of an issue with their children so I was quite pleased I wasn't the one.”

William's wife Kate Middleton, who is pregnant with their third child, was unable to be on hand for George's first day. A spokesperson told People magazine, "Unfortunately The Duchess of Cambridge remains unwell, and will not be able to accompany Prince George on his first day of school. The Duke of Cambridge will drop off Prince George this morning as planned."

Middleton has been battling hyperemesis gravidarum, a severe kind of nausea during pregnancy. Earlier this week, William opened up on Kate's health, saying, "We need Catherine to get over this first bit and then we can start celebrating. It's always a bit anxious to start with, but she's well.”

Ben Thomas, principal of Thomas's London Day School and former head teacher at Thomas's Battersea, said George won't be getting “any special treatment at all.” He told People magazine, "In fact, what his parents would like for him, as any parent would like for their child, is they have a wonderful, fulfilling and private childhood in a place which is secure.”