Madonna's 55, but she's still partying like it's 1999! Or maybe 1770 ...

The Material Girl threw herself a party at her rented mansion in the south of France over the weekend, and dressed as a sexy Marie Antoinette, while boyfriend Brahim Zaibat and all her guests, donned 18th-century costumes.

Queen Madge wore a tall, blonde wig and a heart-shaped eye patch, along with a glittered purple leotard -- she's gotta be the center of attention!

Madonna Tweeted during the night, "Perhaps we had too much Cale! But at my Brithday Party all I could see was LOVE." She followed: "Perhaps I had too much Champagne! I meant to write CAKE!" Beware of #DrunkTweeting on your birthday! #LetThemEatCake!



Check out our HUGE gallery of guest photos and Madonna's FULL Twitter album below! ...