Of Harvard Square’s many byways, few document the passing of time the way Brattle Street does, from the arrival of modern chic stores like Jasmine Sola to the closure of old-time favorites like the Billings and Stover Apothecary.

Yet what is arguably the most nondescript building on Brattle St. has remained the same for half a century.

The Brattle Theatre marks its 50th anniversary this week, and whether its marquee shows classic names like Humphrey Bogart and Ingmar Bergman, or newer ones such as Maggie Gyllenhaal and David Lynch, its tiny lights still attract film buffs from far and wide.

Today, the Brattle’s teeming schedule of classic, avant-garde and new independent films draws a diverse crowd from Harvard and Cambridge.

But when the theater’s walls were first erected, the glow of Hollywood pictures was but a distant light in the future. Originally envisioned as a cultural center that would combine theater, lectures and meetings, Brattle Hall arose from plans drawn by Reverend Samuel Wadsworth Longfellow, brother of poet Henry.

Over the next decades, Brattle Hall housed various professional theater companies, but its pivotal moment came in 1946 through a small advertisement in The Crimson.

Jerome Kitty, a Harvard student who found Harvard dramatic societies “excessively clubby,” ran an ad looking for war veterans who might have interest in starting a theater group.

Kitty’s idea took hold, and the Brattle Theater Company formed, immediately buying Brattle Hall. From 1948 to 1952, the Company occupied the building, bringing the likes of Jessica Tandy, Hume Cronyn and Zero Mostel to play in everything from Shakesperean tragedies to Chekhovian dramas.

By the early 1950s, many of the actors instrumental in the Brattle’s early history had moved on to professional careers in acting. The door was open for change, and in 1953 Cyrus Harvey, Jr. ’47 and Bryan Halliday, both Harvard affiliates, decided to convert the Brattle from a performance space to a movie theater.

Over the next few decades, Harvey and Halliday shaped the Brattle into a cinematic venue that would provide a forum for funky indies, American classics and foreign gems.

One renovation from that era—a rear projection system which burns carbon instead of electric bulbs—is even used today.

It’s not just the lightbulbs that are the same, though. The Brattle’s directors say the relationship between Harvard and the theater continues to be indispensable.

Brattle co-director Ivy Moylan notes various ways in which Harvard has affected the development of the theater, starting in the fifties when “Bogie films”—films starring Humphrey Bogart—were played during reading period and a “Bogie cult” started among students.

And students still make it to the classics at the theater.

“It feels great having college kids continue to come to see classic films, films made long before they were born or their parents were born,” Moylan says. “There is a lot of value in these films—not only do they show us our past but they also show where today’s films come from, where the cinematic references in Donnie Darko, Fight Club or The Matrix originated.”

While other modern theaters—such as the Somerville Theater and Kendall Square Cinema—show movies similar to the Brattle’s, Moylan says her theater stands apart from the rest. The Brattle is the only theater in the Boston area with a functional balcony, an independent association and a range of movies wider than that of the average multiplex, Moylan says.

And the Brattle has always had a fair amount of star power with visiting directors and actors. This year, the Brattle will also launch two awards, the Bogie and the Orson.

Through programs like this, say the Brattle’s management, the creativity of this small building won’t stop any time soon.

“We want to open people’s minds, make them see that film can mean so many different kinds of things,” Moylan says. “The Brattle Theater already has a legacy. We just want it to continue strong into the future.”

—Staff writer Rebecca M. Milzoff can be reached at milzoff@fas.harvard.edu.