Cambridge party-of-five makes grand debut at Prince Louis' christening, plus all the best photos

The British royals and Middleton family gathered at St. James's Palace on July 9 to attend the christening of two-month-old Prince Louis. The newborn Prince's relatives were dressed to impress for the joyous occasion. Click through for all the best photos from the royal affair.

The Cambridge family-of-five made their grand debut at Prince Louis' christening on July 9. Kate Middleton and Prince William stepped out with their baby boy as well as Princess Charlotte and Prince George. The Duke of Cambridge was on full dad duty holding hands with his older children as he led them inside the chapel, while the Duchess cradled her baby boy. The outing marked Louis' first public appearance since being born on April 23.

The royal mom-of-three was beaming with pride at her son's baptism. Kate stunned for the ceremony turning to her go-to designer Alexander McQueen for her elegant dress. The 36-year-old completed her sophisticated look with a hat by Jane Taylor, which was embellished with flowers, and pearl cluster earrings.

Prince George and Princess Charlotte’s baby brother slept soundly in his mother’s arms. Kate was heard describing her sleeping boy as "very relaxed and peaceful.” The Duchess added with a smile: "I hope he stays like this."

Meghan Markle paid homage to her American roots wearing an olive green dress by Ralph Lauren. The former actress completed her outfit with suede Manolo Blahnik pumps, a hat by Stephen Jones and pulling her dark tresses into a sleek ponytail. The Suits alum was baptized earlier this year in the same chapel as Louis.

Ahead of the ceremony, the official royal family Twitter account shared some interesting tidbits about their christening traditions. The palace revealed that "one of the three top tiers of The Duke and Duchess of Cambridge's eight-tier wedding cake will be used for the Christening cake."

Photo: Twitter/@RoyalFamily

Picture of love! Kate doted on her baby boy before entering the chapel. For her older children’s christenings, the Duchess also chose to wear ensembles by her royal wedding dress designer, Alexander McQueen, and hats by Jane Taylor.

The Duchess of Cornwall, who was joined by Prince Charles, coordinated with Kate in ivory wearing a dress by Fiona Clare and a Locke hat.

Princess Charlotte, who was dressed in a floral print dress and a blue bow headband, adorably departed the christening carrying a program tucked under her arm.

Pippa Middleton dressed her growing baby bump in a pastel blue dress by Alessandra Rich that featured a pleated skirt. The mom-to-be, who was joined by her husband James Matthews, teamed the frock with a matching hat and high heels by Jimmy Choo.

Crowds of well-wishers lined the streets outside of the Chapel Royal at London's St. James's Palace to take part in Louis' celebration.

James Middleton arrived to the service with one of Prince Louis’ godparents, Lady Laura Marsham, who is the wife of Prince William's close friend James Meade.

Photo: DOMINIC LIPINSKI/AFP/Getty Images

The Duchess of Cambridge shared a sweet moment with her youngest child after the christening service, while Prince William walked closely behind clasping hands with their firstborn son George and daughter Charlotte.

Following in the footsteps of his older brother and sister, Prince Louis’ christening was conducted by the Archbishop of Canterbury, Justin Welby.

The Duke kept a close eye on his scene-stealing little girl, who sweetly waved as the family left the chapel.

Proud grandparents Michael and Carole Middleton smiled at photographers as they arrived to their grandson’s baptism at the Chapel Royal. Kate’s parents were followed by Pippa and her husband James Matthews.

Photo: DOMINIC LIPINSKI/AFP/Getty Images