Isn't it great that we live in a world where anything could be a cause for celebration? For those of you wondering, July 5th happens to be the official birthday of the summer must-have: the bikini. Introduced by French designer Louis Réardon in 1946, it's hard to imagine what the past 66 years would have been like without the iconic two-piece. See if you can recognize some of history's most iconic "bikini moments" below (via Huffington Post):

Rita Hayworth, 1941
bikinis1.jpg

Ava Gardner, 1944
bikinis2.jpg

Barbara Stanwyck, 1944
bikinis3.jpg

Virginia Mayo, 1944
bikinis4.jpg

Barbara Laage, 1946
bikinis5.jpg

Marilyn Monroe, 1951
bikinis6.jpg

Jayne Mansfield, 1955
bikinis7.jpg

Elizabeth Taylor, 1959
bikinis8.jpg

Ursula Andress in "Dr. No," 1962
bikinis9.jpg

Raquel Welch, 1966
bikinis10.jpg

Phoebe Cates in "Fast Times at Ridgemont High," 1982
bikinis11.jpg

Carrie Fisher in "Star Wars Episode VI: Return of the Jedi," 1983
bikinis12.jpg

Tyra Banks for Sports Illustrated, 1997
bikinis13A.jpg

Angelina Jolie in "Lara Croft: Tomb Raider," 2001
bikinis13.jpg

Halle Berry in "Die Another Day," 2002
bikinis14A.jpg

Cameron Diaz & Demi Moore in "Charlie's Angels: Full Throttle," 2003 
bikinis14.jpg

Jessica Simpson in "These Boots Are Made For Walking," 2005
bikinis15.jpg

Jessica Alba in "Into The Blue," 2005
bikinis15A.jpg

Pamela Anderson's Marriage to Kid Rock in 2006..
bikinis16.jpg

and again for PETA, 2008
bikinis16B.jpg

Helen Mirren, 2008
bikinis17.jpg

Katy Perry in "California Gurls," 2010
bikinis18.jpg

Kate Upton for Sports Illustrated, 2012
bikinis19.jpg