Here's what Pippa Middleton named her baby boy: Arthur Michael William Matthews

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Pippa Middleton welcomed her new bundle of joy in mid-October, but it wasn't until now that we finally have details on the latest Middleton addition, including his name!

According to reports, the Duchess of Cambridge's younger sister opted for three names -- and each moniker holds their own significance.

Welcome, Arthur Michael William Matthews!

Arthur is the middle name of Prince Louis, Prince Charles and Prince William. Meanwhile, Michael is a tribute to both Pippa's father and her husband James' brother, who tragically passed away while trying to climb Mount Everest back in 1999.

Pippa and James welcomed Arthur on October 15th, just three days after the two were spotted at Princess Eugenie's wedding. Arthur joins cousins Prince Louis, Prince George and Princess Charlotte on his mother's side, and new cousin Spencer Matthews on his father's side.

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