Flip through our timeline of Katy Perry's most memorable moments

It's been one birthday after another for Katy Perry; last week she celebrated (rumoured) boyfriend John Mayer's 35th birthday and this week, it's her own big day as she turns 28 on Thursday.

Katy started celebrating her birthday last weekend with a costume party in Los Angeles, where she donned a vampire costume and Mayer dressed as a vampire hunter (geddit?). It was a star-studded party with Kristen Stewart, Skrillex, Ellie Goulding and Neil Patrick Harris among guests. Looks like Katy and Kristen are friends again after the whole Robert Pattinson cheating scandal.

Katy graced our shores just last month, ending the Grand Prix weekend with her usual dose of sugar high.

Want to join in the binge? Flip through our timeline of Katy Perry's most memorable moments, from teen church singer, to teenage dream...