ANIKI-BOBO - The film’s a respected, neo-realist parable.

At 99, Portugal's Manoel de Oliveira is the world's oldest "active" filmmaker. He's also among the greatest. Yet few Americans, even the most avid movie buffs, are familiar with his work. Part of that inequity could be attributed to the fact that only five of Oliveira's 29 features have been commercially distributed in the US.

In honor of his centenary year (he turns 100 in December), a touring retrospective featuring new or archival prints of Oliveira's major works has begun crisscrossing the USA. The Oliveira series ("Manoel de Oliveira: The First 100 Years"), playing at the Cleveland Institute of Art Cinematheque and the Cleveland Museum of Art from May 17 through June 22, is the largest of its kind ever presented in North America. Cinematheque curator Jonathan Forman has been one of Oliveira's leading American cheerleaders for years, and many of the titles screening in the current retro have been shown previously at the 'theque.

Although born in 1908, Oliveira made only three features and a handful of shorts in the first 40 years of his career. After directing his first feature (the well-regarded neorealist parable Aniki­Bobo (May 17) about a group of Porto street kids) in 1942, Oliveira waited 21 years before shooting another film. The right-wing dictatorship of Antonio Salazar, who had come to power in 1932, made life increasingly difficult for anyone living in Portugal. Artists like Oliveira were creatively stifled and effectively silenced during Salazar's authoritarian reign.

During his extended hiatus from directing, Oliveira tended a farm and vineyard inherited by his wife, an experience that he credits with helping him gain the insight needed to become a true filmmaker. "I had time for a long and profound reflection about the artistic nature of cinema," Oliveira explained in a recent New York Times interview.

Released in 1963, Rites of Spring (May 17) would signal a new direction for Oliveira in its mix of fiction and documentary elements (the title refers to a passion play performed in the peasant village of Curlaha). Most of Oliveira's subsequent films are informed by the same dichotomy between film and theater (or literature and film). Randal Johnson, the author of a 2007 monograph on the director, calls Oliveira's attempts to merge the respective mediums a form of "palimpsestic writing." Johnson describes the films as "consistently in dialogue" with existing texts. Because of Oliveira's extensive use of intertitles and voice-overs, the text - whether literary or theatrical in origin - becomes as important as the image. For Oliveira, cinema is a "synthesis of all art forms ... I try to balance the four fundamental pillars of film: image, word, sound and music."

It wasn't until Salazar was finally overthrown in 1974's "Carnation Revolution" that Oliveira would embark upon the most fertile period of his career. Since 1990, Oliveira has directed at least one feature per year. His most recent completed work, 2007's Christopher Columbus, The Enigma (June 19 and 21) starring Oliveira and his wife Maria Isabel, screens twice at the Cinematheque paired with two vintage Oliveira shorts (1931's Labor on the Douro and 1963's The Hunt). While many of the world's greatest actors - including Catherine Deneuve, Marcello Mastroianni, Michel Piccoli and Irene Pappas - have worked with Oliveira, some more than once, his movies are typical arthouse fare. Steeped in history, philosophy, memory, languages and theology, and dealing with themes as heady as the passage of time and its seismic impact on Western civilization, they make precious few concessions to contemporary and/or commercial sensibilities.

Not surprisingly, Oliveira has been repeatedly slammed by philistines as "difficult," the same opprobrium previously leveled against masters such as Carl Dreyer, Robert Bresson, Michelangelo Antonioni, Ingmar Bergman, Jacques Rivette, Jean-Luc Godard and Hou Hsiao-hsien. The French film magazine Cahiers du Cinema once said that Oliveira and his dense, enigmatic, often radical, frequently sublime oeuvre exists in a universe beyond "the rules of cinematic decorum and commerce." And apparently, time itself. Oliveira himself doesn't quite understand why everyone makes such a big fuss about his age. "I see myself being more admired for my age than for my films, which, being good or bad, will always be my responsibility," he remarked. "But I am not responsible for my age."

Manoel de Oliveira: The First 100 Years: May 17-June 22 at Cleveland Institute of Art Cinematheque, 11141 East Blvd., 216-421-7450, and Cleveland Museum of Art Lecture Hall