Katy Perry celebrated her 27th birthday on Tuesday (Oct. 25) -- and for the California pop star, 26 was a year to remember. After releasing her sophomore album, "Teenage Dream," in August 2010, Perry proceeded to embark on a yearlong rule of the Billboard Hot 100, with a massive tour, awards show performances, a handful of hair colors and a new husband along the way.
To honor Perry's b-day, Billboard.com has compiled a timeline of memorable achievements from the pop star's past 12 months. Among the highlights: becoming the first female artist ever to notch five Hot 100 No. 1s from one album, winning Video of the Year at the MTV Video Music Awards, working with artists like Kanye West and Missy Elliott, and kicking off a world tour in February that's still going, and will finally wrap on Dec. 1. Take a look back at Katy Perry's last 365 days -- which of her accomplishments impresses you the most?
Oct. 25, 2010: Katy and Russell Brand fly off to Maldives for their honeymoon, after the couple were married at a tiger reserve in India on Oct. 23.
Nov. 9, 2010: "Glee's" all-male a cappella group, the Warblers, performs a cover of Perry's "Teenage Dream"; the track quickly powers to No. 8 on the Hot 100.
Nov. 21, 2010: Katy performs "Firework" with a gaggle of precocious kids at the 2010 American Music Awards, where she is nominated in three categories.
Dec. 1, 2010: Katy performs "California Gurls" on CBS's "Grammys Nominations Concert Live!!" concert. By the end of the night, Perry has snagged four nominations, including an Album of the Year nod for "Teenage Dream."
Dec. 18, 2010: "Firework," the third single from "Teenage Dream," reaches No. 1 on the Hot 100. "California Gurls" and the album's title track had already hit No. 1 on the Hot 100 in June and September.
Jan. 5, 2011: Billboard names "California Gurls" the top-selling digital song of 2010, with a whopping 4.40 million downloads, according to Nielsen SoundScan.
Jan. 19, 2011: Katy announces the North American dates for her California Dreams 2011 world tour, which featured Robyn and Marina and the Diamonds as support and kicked off June 7.
Feb. 7, 2011: Katy guest stars on CBS's "How I Met Your Mother" as the beautiful, incredibly gullible Honey.
Feb. 13, 2011: Katy performs "Not Like the Movies" and "Teenage Dream" at the Grammy awards, singing the former song as home movies of her wedding were showcased on a large screen behind her.
Feb. 20, 2011: Katy kicks off the European leg of her California Dreams tour in Lisbon, Portugal.
April 9, 2011: "E.T.," Katy's fourth "Teenage Dream" single, reaches No. 1 on the Hot 100. The song gets a boost from a guest appearance by Kanye West.
April 21, 2011: Katy teams up with Kanye to perform "E.T." on Fox's "American Idol."
June 13, 2011: Katy combines an 80s vibe, "Friday" singer Rebecca Black, "Glee" star Darren Criss and a crazy start to the weekend into the John Hughes-aping music video for "Last Friday Night (T.G.I.F.)." The clip has since racked up over 123 million YouTube views.
July 29, 2011: "The Smurfs" hits movie theaters, with Katy lending her voice to the role of Smurfette.
Aug. 8, 2011: Katy recruits Missy Elliott for a remix to "Last Friday Night (T.G.I.F.)," and the track is released to digital retail.
Aug. 27, 2011: "Last Friday Night (T.G.I.F.)" hits No. 1 on the Hot 100, tying Michael Jackson's record for the most No. 1 songs from a single album (five). "Hitting No. 1 is always a great moment, but when it turns into a small piece of history, you're reminded of how many millions of people are connected to each other by even one tiny event," Perry told Billboard when the track hit No. 1.
Aug. 28, 2011: Katy Perry's "Firework" music video takes home Video of the Year at the 2011 MTV Video Music Awards, and Perry accepts the prize with a giant yellow block on her head. Perry and Kanye West also share the stage to claim the trophy for Best Collaboration for the "E.T." clip.
Sept. 17, 2011: "Last Friday Night (T.G.I.F.)" spends its last week in the Top 10 of the Hot 100, ending Katy's record-breaking streak of 69 consecutive weeks with a song in the Hot 100's Top 10, which started on May 29, 2010. The previous record-holder was Ace of Base, who sat in the Top 10 for 48 straight weeks in 1993-94.
Sept. 28, 2011: "The One That Got Away," the sixth single from "Teenage Dream," starts at mainstream top 40 radio stations. The song debuts at No. 94 on the current Hot 100.
(Additional reporting by Gary Trust)