Nicholas Hytner is to return to the Royal Opera House after 20 years.

The National Theatre director will present a new production of Verdi's five-act grand opera Don Carlo from June next year, it was announced today.

Covent Garden's 2007/08 season, unveiled today, also includes the complete four-opera cycle of Wagner's The Ring, to be staged three times between 2 October and 2 November. Placido Domingo and Bryn Terfel return to the venue for the Norse epic.

Hytner last directed at Covent Garden in 1988, when he took on Michael Tippett's The Knot Opera.

Opera House executive director Tony Hall said: "It's fantastic we have got Nick Hytner back. I know Don Carlo is his favourite opera, as it is mine."

Also returning is Deborah Voight - after she lost more than 10 stone. The soprano has been rehired for the title role in Richard Strauss's Ariadne Auf Naxos, which she lost in 2004 after not being able to fit into the costume, a little black dress. Since then, she has had a gastric bypass.

The season will also see the world premiere of The Minotaur, the Royal Opera's second commissioned work by British composer Harrison Birtwistle. It will be conducted by Covent Garden's music director Antonio Pappano. The title role has been created for English bass John Tomlinson, 60.

Mr Hall said: "One of the great highlights is this new production from Birtwistle. It shows opera still has things to say and can move forward."

The season opens with Christoph Gluck's Iphigénie en Tauride, with Susan Graham and Simon Keenlyside - nominated for singer of the year at the Classical Brit awards - in the principal roles.

Other highlights include Salome, The Rake's Progress and a new production of Donizetti's L'elisir d'amore, starring Rolando Villazón.

Two Christmas productions are Rossini's comic opera La Cenerentola, starring Magdalena Kozena in her Royal Opera debut, and a revival of Richard Eyre's production of La Traviata with Anna Netrebko and Jonas Kaufmann.

The new season of The Royal Ballet was also revealed - with the announcement that conductor Barry Wordsworth has been appointed music director.

The season's highlight will be a complete production of George Balanchine's Jewels. Created in 1967 for New York City Ballet, it comprises three ballets named after different gemstones, each with music by a different composer.

Emeralds, with music by Fauré, evokes French romanticism; Rubies, set to Stravinsky's Capriccio for Piano and Orchestra, is inspired by Broadway; and Diamonds, with movements from Tchaikovsky's Third Symphony, is a homage to the classicism of St Petersburg.

There will be five other full-length ballets - La Bayadère, Romeo And Juliet, The Nutcracker, Sylvia and The Sleeping Beauty.

A Christmas double bill takes in Frederick Ashton's Les Patineurs and Tales Of Beatrix Potter.