Christophers founded the vocal ensemble The Sixteen in 1979. He has directed The Sixteen and its orchestra throughout Europe, America and the Far East, becoming recognised for his work in Renaissance, Baroque and 20th-century music. With The Sixteen he has conducted recordings for CORO and other labels including Hyperion Records, UCJ and Virgin Classics. Several recordings have received honours such as a Grand Prix du Disque and a Midem award for Handel's Messiah, numerous Schallplattenkritik, the Gramophone Award for Early Music and the Classical Brit Award 2005 for the disc Renaissance. The Sixteen's 2009 recording of Handel's Coronation Anthems earned a Classic FM Gramophone Award in the Baroque Vocal category as well as Artist of the Year honours for Christophers and The Sixteen. The recording also earned Christophers a Grammy nomination for Best Choral Performance. In 2000, Christophers began the "Choral Pilgrimage", a national tour of English cathedrals from York to Canterbury, in music from the pre-Reformation era as The Sixteen's contribution to the millennium celebrations. This then led to subsequent annual pilgrimages devised around particular themes. As part of The Sixteen's thirtieth anniversary in 2009, the ninth pilgrimage was dedicated to the anniversaries of Henry Purcell, James MacMillan and George Frideric Handel. The 2011 pilgrimage focused on the music of Tomás Luis de Victoria and the 2012 pilgrimage, entitled "The Earth Resounds", explores the sacred music of Flanders in the 15th and 16th centuries by composers Josquin, Brumel and Lassus. In September 2008, Christophers was named the Artistic Director of the Handel and Haydn Society in Boston, Massachusetts, beginning in the 2009–2010 season, for an initial contract of three seasons. In September 2011, his contract with the Handel and Haydn Society was extended another four seasons until the 2015–2016 season, in time for the organisation's bicentennial celebrations. Increasingly busy in opera, Christophers has conducted numerous productions for Lisbon Opera and English National Opera as well as conducting the UK premiere of Messager's opera Fortunio for Grange Park Opera. He is a regular conductor at Buxton Opera where he initiated a cycle of Handel's operas and oratorios including Semele, Samson and Saul. Christophers is an Honorary Fellow of Magdalen College, Oxford, as well as the Royal Welsh College of Music and Drama and has been awarded the honorary degree of Doctor of Music from the University of Leicester. Christophers is also Patron of the in Nottinghamshire. He was appointed a Commander of the Order of the British Empire in the 2012 Birthday Honours for services to music.