Prince George of Cambridge started his royal education in earnest Thursday, arriving for his first day of school — with non-royal kids.

He was accompanied by his father the Duke of Cambridge. George's pregnant mother, Duchess Kate of Cambridge, 35, was too ill with morning sickness to take part in the drop off. 

The 4-year-old heir (he's third-in-line to the throne) let Prince William carry his backpack when he arrived at Thomas's Battersea, the well-regarded private day school across the River Thames a few miles from his family's home in Kensington Palace in London. 

George wore the school uniform: navy shorts and jacket, long red socks, and black shoes. 

The Duchess is pregnant with the royal pair's third child and suffering from the acute morning sickness she has experienced in her previous pregnancies. 

The fact that Prince William, 35, accompanied his son to school is a milestone of sorts. His own father never accompanied him to school in the 1980s. 

But George is no ordinary student. He's the grandson of Prince Charles the Prince of Wales and the late Princess Diana, and the great-grandson of Queen Elizabeth II and her husband Prince Philip. He's one very important kindergartener.   

As George settled in for his first day of real school (previously he attended a Montessori pre-school near the family country retreat in Norfolk), speculation swirled about what he will be called in school records and what name will be stenciled on his backpacks.

George Windsor? George Wales? George Cambridge? Probably the latter, with the possible addition of HRH.

When George's father Prince William and uncle Prince Harry were in school, they used the last name Wales because their father is the Prince of Wales. But now William's official title is the Duke of Cambridge.

Whatever he's called, Thomas's Battersea is delighted to have him, and his parents are delighted with their choice of the prep school on the south bank of the Thames. 

"Their Royal Highnesses are delighted to have found a school where they are confident George will have a happy and successful start to his education," their statement said at the time of the announcement in March. 

Ben Thomas, the headmaster at Thomas's Battersea, said the school is "honored and delighted. We greatly look forward to welcoming him and all of our new pupils to the school in September," he said at the time in a statement.

The other students include many from the upper-class neighborhood of Battersea. On its website, the school, one of four family-run schools, describes itself as a "busy, thriving, purposeful school" with about 540 students between ages 4 and 13 and a curriculum that includes art, ballet, drama, French, music, and physical education.

For George's many fans, his daily runs to and from school might offer a chance to catch more glimpses of the little prince. However, his parents are hoping he'll be left alone after the hullabaloo of the first day.

To avoid the media mobs who attended Will and Harry's first days of school with Diana back in the 1980s, Will and Kate have arranged for more low-key coverage, with just a small pool of photographers on hand to record history. 

George is only the third generation of the royal family to attend an actual school; prior to Prince Charles' generation, royal children were schooled in early years by tutors and governesses in royal palaces, then sent off to Eton if they were boys.

Now it's possible that 2-year-old Princess Charlotte, George's equally adorable little sister, could attend Thomas's Battersea, too, in a few years. 

Contributing: The Associated Press