Happy birthday, Britney Spears! Today, America's Pop Princess turns 30-years-old. 

It has been quite a whirlwind ride since the blonde bombshell entered the scene in 1999 with her smash chart-topper, Hit Me Baby One More Time. No one had seen a singer quite like her - a sweet Southern Belle with a killer body. Spears quickly became America's Pop Princess. 

From there, she skyrocketed to worldwide fame. She endorsed Pepsi, dated Justin Timberlake, wore a body-stocking, danced with a snake, broke up with Justin Timberlake, partied, dated Kevin Federline, had two babies, gave a ghastly VMA performance, shaved her head and is now back on top where she belongs.

She has entered the hearts of Americans because behind that bleach blonde hair and toned, cut body is just a sweet simple girl. America could not look away as Britney grew up, messed up and made a big comeback. 

Although her life has seemingly been a rollercoast, Spears seems to be happy and settled. She is currently dating Jason Trawick, who is supposedly ready to pop the question! 

People magazine reports that sources say Trawick, 39, has already chosen a ring. They've been talking about marriage for a long time, says the source. It would be surprising if they are not engaged by the end of the year.  

And, of course, her music was completely catchy and delicious. America could not get enough of Oops I Did It Again, I'm a Slave 4 U, and Womanizer. Spears surely knows how to churn out the hits. 

Her fashions have always been eye-popping as well. It all started with the schoolgirl uniform, then the sparkling bodysuit, the matching denim suits, the yellow boa, the pleather, the glitter and the lace. Spears certainly knows how to stand out in a crowd. 

Britney is really looking forward to turning 30. She is having one of the best times of her life, said the source to People.  

So in honor of Spears' 30th year, let us take a look back on her style evolution.