In 1957, when the Berlin International Film Festival was in its sixth year and the Festival de Cannes had recently turned 12, there was still no established annual film festival in the U.S. “Back in the ’50s, San Francisco needed to keep its place in the arts world with an international film festival. There wasn’t one in North or South America,” San Francisco International Film Festival (SFIFF) founder Irving M. “Bud” Levin recalled in 1995.

Following Levin’s lead, the San Francisco Film Society has presented the SFIFF since 1957 and becomes the first North American festival to celebrate its 50th anniversary when the event unreels April 26-May 10 at various Bay Area venues. Now a sprawling 15-day celebration of global cinema, the inaugural fest was a relatively modest affair, screening an international title every night over two weeks to stylishly attired audiences at Union Street’s Metro Theater.

The first SFIFF included Michelangelo Antonioni’s Il Grido, Akira Kurosawa’s Macbeth adaptation Throne of Blood, Satyajit Ray’s first Apu-trilogy installment Pather Panchali and Luchino Visconti’s Senso, as well as Uncle Vanya – the only American film in the lineup.

“The history of achievements of the festival is a very, very long one,” says Graham Leggat, who joined the San Francisco Film Society as executive director in October 2005. “To begin with, the fact that in 1957, when America was scared of aliens of all descriptions, both invaders from outer space and the Red menace, we were showing 15 films from 12 different countries. You can’t imagine nowadays exactly how revolutionary that was.”

Fifty years later, the 2007 SFIFF offers titles from 54 countries, bookended by two award-winning European films. Emanuele Crialese’s New York-set Sicilian-immigrant saga Golden Door (Nuovomondo) opens the run and two weeks later the festival closes with director Olivier Dahan scheduled to attend the West Coast premiere of La Vie en Rose, the Edith Piaf biopic that recently kicked off the Berlin festival.

The SFIFF has a variety of special awards and events on tap for the 50th, in addition to annual filmmaker and actor tributes scheduled for the May 3 Film Society Awards Night gala, when legendary Bay Area writer, director and producer George Lucas receives the one-time Irving M. Levin Award in recognition of his commitment to cinema arts. That same evening, Robin Williams will be honored with the Peter J. Owens acting award and acclaimed writer Peter Morgan (The Queen, The Last King of Scotland) will be the recipient of the Kanbar Award for excellence in screenwriting. The Directing Award will go to iconoclastic filmmaker Spike Lee, whose post-Katrina documentary When the Levees Broke [pictured above] shows in a special program, more than 20 years after She’s Gotta Have It first played the SFIFF.

Among the fest’s golden anniversary events, Leggat will co-host “Five-0: Stories and Images From 50 Years of the SF International,” an onstage oral-history retrospective profiling the SFIFF’s five-decades, with special guests, photo montages and film clips.

The strong showing of veteran directors spread across festival programs and scheduled to attend the event is a manifestation of the long-term artistic relationships that festival organizers have built over the decades. “The history of ferreting out and showcasing cinema from countries whose national cinemas had hardly been heard of that [former SFIFF director] Peter Scarlet did in his tenure here is nothing short of superb,” says Leggat. “Whether it was [Abbas] Kiarostami or whether it was the Koreans, we’ve always had a nose for great film.”

That talent for selecting intriguing new filmmakers is also reflected in the competitive SKYY prize narrative program, which features a $10,000 cash award and showcases the work of 11 first-time directors, including John Barker’s South African road trip picture Bunny Chow and Sundance 2007 competition entry How Is Your Fish Today? from Xiaolu Guo.

The San Francisco premiere of Guy Maddin’s color/B&W silent Brand Upon the Brain! — a “faux-autobiographical” multimedia melodrama supported by a 13-piece musical ensemble and Foley crew — highlights a selection of music and film events. Similarly ambitious, cult favorite singer-songwriter Jonathan Richman brings his unique interpretive skills to bear on an original live score for the new 35mm print of Victor Sjöström’s 1921 silent surrealistic fantasy The Phantom Carriage.

Contemplating the innovations that he and his staff have introduced in the 18 months that he’s been overseeing the San Francisco Film Society, Leggat reflects that “The things that we’ve added are an emphasis on digital media and basically the social contacts that should surround any good festival,” including such year-round activities as the SF360.org Bay Area film industry news website (co-published with indieWIRE) and a monthly SF360 TV show on Comcast. “Our job all along for 50-odd years has been exploration and discovery, so we’re continually pressing forward,” notes Leggat.

New digital initiatives this year include SFIFF’s GreenWorld Contest, an online competition for short films on the theme of global sustainability, which offers a $1,000 cash prize and festival exhibition, co-sponsored by Yahoo! Video and Jumpcut. Yahoo! Video will also stream festival content on a dedicated online channel throughout the event and beyond.

“The festival has been visionary right from the start and it’s only managed to maintain its position of prominence and to exist at all because it’s continued to adapt,” Leggat observes. “It’s no small feat to be the first festival in the Americas to reach the 50-year milestone.”