MAYBE it started with the Lethal Weapon series. Back in 1988, when the director Richard Donner was looking to fill the role of Mel Gibson's love interest in Lethal Weapon 2, he followed the formula laid out in every casting director's dust-covered handbook.
He chose 20-year-old Patsy Kensit to play a smooth-skinned and naive young thing opposite the 32-year-old actor. But Patsy took a bullet, so when the time came to shoot Lethal Weapon 3 in 1991, Donner found himself playing matchmaker again. This time, though, he went with the unexpected: Rene Russo, a woman who was Gibson's equal in every way - including age.
''Dick likes the fact that she was in her 30s and not some ingenue,'' says Lauren Schuler-Donner, the director's wife and adviser on all three Lethal Weapons. After years of modelling and a string of so-so roles in so-so films (One Good Cop , Mr Destiny ), Russo found herself in one of the year's top-grossing movies. The director, Wolfgang Peterson, saw her Lethal performance and hand-picked her to star opposite Clint Eastwood in this summer's In The Line Of Fire - another potential blockbuster.
So, at the age of 38, Russo now finds herself approaching Hollywood's elite group of A-list actresses. For a woman to hit her stride at that age in this town would have been unheard of a few years ago. And Russo is not alone. This summer, Sela Ward, 35,will get her first real crack at feature film stardom, opposite Harrison Ford in The Fugitive. Thirty-five-year-old Sharon Stone romances William Baldwin - a man six years her junior - in Sliver . Stone leads a select group of the most powerful and sought-after actresses in Hollywood, all in their 30s. There is Michelle Pfeiffer, 34; Annette Bening, 35; Geena Davis, 36; Demi Moore, 30; Jodie Foster, 30; Melanie Griffith, 36; Andie McDowell, 35, Ellen Barkin, 38; and Emma Thompson, 34.
While twentysomething starlets certainly haven't disappeared from the screen - Julia Roberts, 26, is set to shoot The Pelican Brief later this year - women in their 30s have been quietly but dramatically taking over many of the choicest roles.
Over the years, many powerful actresses have been able to hold on to their stardom past their 30th birthdays - there were Bette Davis, Audrey Hepburn and Joan Crawford, to name just a few. What makes the current crop of stars unique is that many of them,like Stone and Russo, didn't become household names until they reached their 30s. ''That you can still be made a star at Sharon Stone's age, well this is a first,'' says the casting director of Desperately Seeking Susan, Billy Hopkins.
Why are we seeing this sudden mid-30s surge? One key factor behind the ''breakthrough'' is - no surprise - Hollywood's men. With the exception of Costner and Cruise, today's leading men (Harrison Ford, Michael Douglas, Arnold Schwarzenegger, Sean Connery, Clint Eastwood) are either well into their 40s, entering their 50s or, dare we say it, pushing 60.