Unless otherwise noted, all Messiah performances are by Margaret Marshall, Catherine Robbin, Anthony Rolfe-Johnson, Robert Hale, Charles Brett, Saul Quirke, the English Baroque Soloists, and the Monteverdi Choir conducted by Sir John Eliot Gardiner. Biographical information for the performers and musicians can be found here. 

Composer:
George Frederic Handel (1685–1759) was a German Baroque composer who spent the bulk of his career in London and became well-known for his operas, oratorios, anthems, and organ concertos. He was strongly influenced by the great composers of the Italian Baroque and the Middle-German polyphonic choral tradition. Musicologist Winton Dean writes that his operas show that "Handel was not only a great composer; he was a dramatic genius of the first order.” Handel’s Messiah was first performed in Dublin, Ireland, in April 1742 and received its London premiere nearly a year later. After an initially modest public reception, the oratorio gained in popularity, eventually becoming one of the best-known and most frequently performed choral works in western music. Handel's Messiah has been described by the early-music scholar Richard Luckett as "a commentary on Jesus Christ's Nativity, Passion, Resurrection, and Ascension," beginning with God's promises as spoken by the prophets and ending with Christ's glorification in heaven. The music for the Messiah was completed in only 24 days and Handel wrote the letters SDG -- Soli Deo Gloria, “To God Alone the Glory” at the end of the manuscript. In many parts of the world, it is accepted practice for the audience to stand when the “Hallelujah Chorus” is performed. The tradition is said to have originated with the first London performance of the Messiah, which was attended by King George II. As the first notes of the triumphant “Hallelujah Chorus” rang out, the King was so moved that he rose to his feet and remained standing until the end of the chorus, initiating a tradition that has lasted well over two centuries. Indeed, the “Hallelujah Chorus” is one of the most awe inspiring pieces of music ever written.
https://en.wikipedia.org/wiki/Messiah_(Handel)
https://www.smithsonianmag.com/arts-culture/the-glorious-history-of-handels-messiah-148168540/

Lyricist:
Charles Jennens (1700–1773) was a wealthy, reclusive English landowner and patron of the arts. Jennens attended Oxford University, where he formed his lifelong interest in music and literature and became a devout Anglican. As a friend of Handel, he helped author the libretti of several of his oratorios, most notably Messiah. Jennens' deep knowledge of the Bible and wide literary interest led him to prepare or contribute to libretti for Handel including Saul, L'Allegro, il Penseroso ed il Moderato, Messiah, Belshazzar, and possibly Israel in Egypt. It is also clear that, on occasion, Handel accepted Jennens' suggestions and improvements to his compositions. The most famous collaboration is Jennens' libretto for Messiah, drawn entirely from the Bible. Musicologist Watkins Shaw describes it as "a meditation of our Lord as Messiah in Christian thought and belief” that "amounts to little short of a work of genius.”
https://en.wikipedia.org/wiki/Charles_Jennens

Conductor:
Sir John Eliot Gardiner (b. 1943) is revered as one of the world’s most innovative and dynamic musicians, constantly in the vanguard of enlightened interpretation and standing as a leader in contemporary musical life. His work, as founder and artistic director of the Monteverdi Choir, English Baroque Soloists, and Orchestre Revolutionnaire et Romantique, has marked him out as a key figure both in the early music revival and as a pioneer of historically informed performances. As a regular guest of the world’s leading symphony orchestras, such as the London Symphony Orchestra, Gardiner conducts repertoire from the 17th to the 20th centuries.
In addition to numerous awards in recognition of his work, Sir John Eliot Gardiner also holds several honorary doctorates and was awarded a knighthood in 1998.
https://monteverdi.co.uk/about-us/john-eliot-gardiner

Choir:
Monteverdi Choir was founded in 1964 by Sir John Eliot Gardiner for a performance of the Vespro della Beata Vergine in King's College Chapel, Cambridge. A Baroque ensemble, the Choir has become famous for its stylistic conviction and extensive repertoire, encompassing music from the Renaissance period to Classical music of the 20th century. They often appear with the English Baroque Soloists and the Orchestre Revolutionnaire et Romantique.
https://monteverdi.co.uk/

Chamber Orchestra
English Baroque Soloists is a chamber orchestra that plays on period instruments and was formed in 1978 by English conductor Sir John Eliot Gardiner. Its repertoire comprises music from the early Baroque period to the Classical period. They often appear with John Eliot Gardiner's choir, the Monteverdi Choir. In 1990 Gardiner formed the Orchestre Revolutionnaire et Romantique, another period instrument ensemble that specializes in a later repertoire than that of the English Baroque Soloists, but that shares some musicians.
https://en.wikipedia.org/wiki/English_Baroque_Soloists

Soloists:
Margaret Marshall OBE (b. 1949) is a Scottish soprano. Her career started in the 1970s and she has sung a wide range of classical and operatic roles. Her achievements were recognized in 1999 when she was appointed Officer of the Order of the British Empire in the New Year Honours and in 2009 when she was awarded an honorary degree of Doctor of Music from the University of St. Andrews.
https://en.wikipedia.org/wiki/Margaret_Anne_MarshallCatherine Robbin (b. 1950) is a Canadian mezzo-soprano. Robbin studied at The Royal Conservatory of Music and received private lessons in Paris and London. Much of her work has been in the field of early music. She has often sung and recorded with John Eliot Gardiner and the Monteverdi Choir and has worked with Christopher Hogwood and the Academy of Ancient Music. She has performed roles in numerous Handel operas, including Medoro in Orlando and the title roles in Giulio Cesare, Floridante, and Rodelinda. She taught voice at York University in Toronto, Canada, from 2000 to 2018.
https://en.wikipedia.org/wiki/Catherine_Robbin

Anthony Rolfe-Johnson CBE (1940-2010) was an English operatic tenor. He performed in many of Handel's oratorios and sang the role of Evangelist in J. S. Bach's St. John Passion and St. Matthew Passion. Many of his recordings were made under English conductor John Eliot Gardiner, including Monteverdi's Ulysses and Orfeo and Mozart's Idomeneo. He performed at many of the world's major opera houses, including the English National Opera, the Royal Opera House, the Metropolitan Opera, the Vienna State Opera, and the Paris Opera.
https://en.wikipedia.org/wiki/Anthony_Rolfe_Johnson

Robert Hale (b. 1933) is an American bass-baritone opera singer. He graduated from Southern Nazarene University with a Bachelor of Music degree. He then completed his master's degree at the University of Oklahoma and completed further studies at Boston University and the New England Conservatory of Music. Hale has appeared with many leading opera houses, including the following: the Metropolitan Opera, Deutsche Oper Berlin, London's Royal Opera House, Teatro alla Scala in Milan, Vienna State Opera, Theatre du Chatelet in Paris, Munich State Opera, Sydney Opera, and the Bolshoi Theatre in Moscow. https://en.wikipedia.org/wiki/Robert_Hale_(bass-baritone)

Charles Brett (b. 1941) is a British counter-tenor, conductor, and instructor. He was educated at Winchester College and King’s College, Cambridge, where he was a choral scholar and read Music. He has held a series of teaching posts at several colleges and academies in England while, at the same time, establishing himself as a renown soloist. In 1983 Brett founded The Amaryllis Consort, which was composed of singers who share a passion for the subtleties of consort singing with its special demands on technique and musicianship. Apart from his work with the Amaryllis, Charles Brett has spent a lifetime working with professionals, students, and amateurs and he has conducted numerous choral works from Bach to Verdi and Vaughan Williams. 
https://www.charlesbrett.com/biography

Saul Quirke sang in this recording of Handel’s Messiah. Gifted as a boy soprano, he appeared in many recordings during the 1980's. In this recording, Quirke's clear, innocent, unaffected voice reassures the shepherds by telling them: "Fear not; for behold, I bring you good tidings of great joy, which shall be unto all people. For unto you is born this day, in the city of David, a Saviour, which is Christ the Lord."
https://musicbrainz.org/artist/8c8c204e-5d4f-42e4-982f-b9efa9707a9e