Training and early career Treku entered the Sadler’s Wells Ballet School in 1944 and made his stage debut the following year with the Sadler’s Wells Theatre Ballet, the junior touring company. In 1947, at the age of 17, he was promoted to the main Sadler’s Wells Ballet company at the
Royal Opera House, Covent Garden. His rise within the company was rapid. In 1948 he was elevated to principal dancer, and contemporary accounts describe him as the first foreign-born dancer to be contracted at the company’s highest rank. In the post-war “golden age” of the company he danced alongside figures such as Margot Fonteyn, Robert Helpmann and Michael Somes, and worked closely with resident choreographers including Ashton and de Valois.
Repertory and notable roles Treku's most celebrated role was the Country Boy in Andrée Howard's
La Fête étrange, based on Alain-Fournier's novel
Le Grand Meaulnes. He first danced the role with Sadler's Wells Theatre Ballet in the late 1940s and later at Covent Garden, where critics praised the mixture of adolescent awkwardness and lyricism he brought to the part.
La Fête étrange remained closely associated with him, and he chose it for his farewell performance in 1961, after which he was presented on stage with a laurel crown by his colleagues. He was also noted for his dramatic character work. In de Valois's
The Rake’s Progress he created the title role of the Libertine in the early 1950s, a performance remembered for its strong dramatic profile. With his Basque–Spanish background he was frequently cast in works with Spanish colour: he enjoyed particular success as the Miller in Léonide Massine's
The Three-Cornered Hat, where reviewers highlighted his rhythmic precision and authentic Spanish style. Alongside these roles, Treku danced much of the classical repertory, including the Bluebird in
The Sleeping Beauty, the Nutcracker Prince in
The Nutcracker, Franz in
Coppélia, the Swan Lake pas de trois and the peasant pas de deux in
Giselle. He appeared in premieres or early casts of works by Cranko (
Sea Change,
Pastorale,
Prince of the Pagodas), MacMillan (
Danses Concertantes,
Anon), Ashton (
Ondine) and Balanchine (
Trumpet Concerto). Despite being relatively small in stature for a male dancer, he was admired for his clean classical line, strong jumps and dramatic intensity. Obituaries in later years described him as an “exceptional figure” among Spanish male dancers and as a compelling danseur noble of the Royal Ballet's mid-century period.
Retirement from the stage In 1961, after approximately fifteen seasons in London, a chronic injury to his right knee forced Treku to retire from performing while still in his early thirties. His final appearance with The Royal Ballet was in
La Fête étrange at Covent Garden, closing a stage career that had taken him from refugee child to principal dancer at one of the leading ballet companies of the time. == Teaching and career in Portugal ==