princechristening460.jpgJohn Stillwell for Getty Images

It was a big day for the little guy!

Prince William and Kate Middleton were beaming as they showed off son Prince George at his christening service today, and we can't believe how much the little heir has grown since his birth back in July!

The 35-minute private ceremony began at 3p.m. London time at the Chapel Royal in St. James Palace.

"The Duke and Duchess of Cambridge have chosen two hymns, two anthems and two lessons for the service," the palace said in a statement.

Prince Harry and Pippa Middleton were on hand for the ceremony. Zara Phillips, William van Custem, Jamie Lowther-Pinkerton, Olivia Baker, Emilia Jardine-Paterson, Earl Grosvenor, and Julia Samuel were chosen as godparents.

History in the making!