Kepler's Trial: An Opera

by Tim Watts based on Ulinka Rublack's book The Astronomer & the Witch
and film elements by Aura Satz.

Lydia and Manfred Gorvy Lecture Theatre,
Victoria and Albert Museum, London.

Thursday 9 November 2017.

Book Now


An overview of the Opera

Update: The next performance of the opera Kepler's Trial by Tim Watts will be held at the Lydia and Manfred Gorvy Lecture Theatre, Victoria and Albert Museum, Cromwell Road, Knightsbridge, London, SW7 2RL on Thursday 9 November 2017.

- to comprise:

(i) a pre-performance event commencing at 18.30 with Profs Dame Marina Warner, Ulinka Rublack, Simon Schaffer, Aura Satz and Tim Watts

(ii) an evening performance commencing at 20.15 and ending at approximately 21.45

To book tickets and find out more information, click here.

Johannes Kepler (1571-1630) is one of the most admired astronomers who ever lived. He defended Copernicus's sun-centred universe and defined the three laws of planetary motion. Less well known is the fact that in 1615, when Kepler was at the height of his career, his old, widowed mother Katharina was accused of witchcraft in a Lutheran town in Germany.. The proceedings led to a criminal trial, with Kepler conducting his mother's defence to fight for legal justice. Kepler's Trial responds to Paul Hindemith's Opera Harmony of the World and other accounts which present Katharina Kepler as deranged, witch-like woman. Based on Ulinka Rublack's book The Astronomer & the Witch the opera and film explore with empathy and nuance what it meant for Johannes and Katharina to face the trauma of an accusation of witchcraft, before and after the trial. The opera is the culmination of a highly unusual creative process, in which a team of leading scholars met regularly to explore the story. The film tells the story of the project, which has been funded by St John's College Cambridge and Cambridge University and is directed by Ulinka Rublack.

Smiley face

With kind support from The Embassy of Germany, London.


From the Opera Premiere


Why Opera?

Opera was born during Kepler’s lifetime. It defined a notion of modernity just as Kepler’s work inhabits another one intellectually. It celebrated the power of music, as an enhancement of speech and sometimes a substitute for it. In his writings, Kepler understands the effect of music on human emotion as linked directly to its embodiment of cosmic harmony. We vibrate in sympathy to its evocation of divine order and respond equally to the disruptions to this order generated by dissonance. His insistence on the interconnection of sensory experience and the organisation of the universe makes his worldview intrinsically operatic. Like Kepler, Claudio Monteverdi, the composer of the one of the earliest operas, L’Orfeo (1607), was a figure who existed on the cusp of the transition from the old to the new. Both also met with hostility from those who viewed their ideas as a threat to established traditions.

The variety of vocal and instrumental forms and textures of L’Orfeo, which juxtaposes recitative, arioso, ritornello, dances and madrigalian choruses, is one of the models for the opera, along with the passions of Bach, which are reflected in the presence of chorales and the contrapuntal style of some of the choral interjections. Musical ‘found materials’ such as the drinking song, modelled on examples by Johann Hermann Schein, are used not just for historical flavour, but for the ways in which they can be transmuted ‘alchemically’ into new and unfamiliar things, taking on new meanings and emotional weight within the world of this story.

Composer Tim Watts discuss his inspiration behind the music for the Opera.

Kepler is introduced with the support of a sonorous quintet of cornetts and sackbuts, while Katharina’s isolation and fragility are coloured, when we first meet her by a harpsichord. At the core of the instrumental ensemble is a sextet of soloistic violins – six, individual planets, perhaps, functioning as a mini-solar system within the whole ensemble.


Knowledge, Illusion and the Figure of the Aged Woman

Dr Victoria Avery, Keeper of Applied Arts at The Fitzwilliam Museum, Cambridge talks talks about the German Renaissance sculpture of the old woman which inspired Ulinka and Aura.

The film elements in the opera by Aura Satz are a response to Ulinka's book and Tim's opera libretto, as well as the many ideas that emerged through the meetings at St John's College, Cambridge. It features a selection of objects from the Whipple Collection for the History of Science and the Fitzwilliam museum. Many of which were filmed rotating on a hand-cranked turntable. This became a key structural device, an illustration of Kepler's cosmological interests, but also as a formal means of shifting, inverting or reconceptualising viewpoints, from Kepler's voice to that of his mother. It resonates also with the lenses and mirrors of featured optical devices such as the telescope and the camera obscura, as well as with a naturalistic German Renaissance sculpture of an old woman and the fearful imagination of old witches at the sabbath, by the early seventeenth-century Dutch artist van Gheyn.


Drama, intrigue and 17th century drinking songs

Katharina is put centre-stage through the use of as many of her own recorded words as possible, supplemented in the case of her first appearance in the opera with a contemporary rhyme on the ages of womankind, which she utters as a reflection on her plight. These are fragments of her own voice – prayers, responses to cross-examination – preserved in trial transcripts. These glimpses of her personality, her faith and her resilience under cross-examination are tiny snapshots, but, in the necessarily constricted word count of a libretto they become substantial, set-piece statements.

Two Lutheran chorales (both with music by Melchior Vulpius) are further examples of primary source material used in the opera to evoke the Leonberg community's fear of darkness.

In prison, Katharina sings a psalm in the eloquent words of the King James Bible. Its Shakespearean qualities also provide a stylistic source for much of the invented portion of the text. Kepler is envisaged as a tragic, prophetic figure, thundering against superstition. His words frequently allude to the planetary preoccupations of his work (although not to the same extent as in Hindemith’s Die Harmonie der Welt, in which the third law of planetary motion is set to music).

The opera is framed by visitations from a Daemon. This character is Kepler’s own literary creation, used in the preface to his strange work of proto-science-fiction, the Dream, to provide the supernatural means for a mother and her son to fly to the moon.

Professor Simon Schaffer and Professor Nick Jardine review the creative process of how the libretto was made.

When, after the trial, Kepler discovered the manuscript of this story, he was filled with horror at the thought that he had unwittingly written the script for the prosecution of his own mother as a witch.

View the full libretto. (PDF)

View the full synopsis. (PDF)

Watch the full performance of the Opera

Johannes Kepler

A unique scientist

Kepler is often seen as a champion of rational thinking that mechanized the universe. In fact, our neat distinctions between religion and magic, the rational and irrational obscure how knowledge about nature and humans mattered to him. This in turn explains connections between some of his ideas and those of his mother. Both saw the earth as alive and the micro- and macrocosm as interlinked. What happened to a living tree or star, might register in your body. Above all, the world was always God's creation, and Kepler was inspired by the belief that nature could reveal traces of God as its maker. Humans were created in God's image. Musical octaves even touched 'ignorant folk', and dance-steps followed geometrical patterns. The world was something far more fascinating than a mechanical clock-work, and Kepler's interest in music was related to his fascination both with regularity as well as surprise, creativity and renewal. In contrast to many at the time, Kepler wrote nothing about the devil as a force. Instead he politically championed the possibilities of religious peace and social advances through new learning. The accusation that he might have been raised by a woman bound to the devil was particularly shocking for him in this sense.

Professor John Toland explains why Johannes Kepler is one of the most important astronomers of all time.

The Astronomer & the Witch

Praise for Ulinka's book

Ulinka Rublack shows wonderful sensitivity about mothers, old age, and female struggles, as she unpicks the trial of Johannes Kepler's mother for witchcraft. (Marina Warner, Book of the Year 2015, Observer)

Excellent ... meticulously researched and wonderfully readable. (John Banville, Literary Review)

[A] superb study ... The author wanted her book to provide a "better understanding of individuals, but also of families, a community, and an age". It succeeds triumphantly. (Jonathan Wright, Catholic Herald)

In 1615, an illiterate widow is accused of witchcraft in a German town. Her son, the famous astronomer Johannes Kepler, conducts her defence in a trial that drags on for six years. In this enthralling book, Ulinka Rublack reconstructs the struggle over Katharina Kepler's fate. We enter a small-town world of rivalries, friendships, deference, power and vulnerability, a world in which religious faith, scientific knowledge and folk belief are dangerously intertwined. Vividly drawn and subtly observed, The Astronomer and the Witch opens a window onto the inner life of a past that is strange and remote, but also unsettlingly familiar. (Christopher Clark)


Key dates in Johannes Kepler's Life, 1571-1620

  1. 1571

    Johannes Kepler born on 27 December in Weil der Stadt; his parents are Heinrich Kepler and Katharina Kepler, née Guldenmund.

  2. 1575

    The Kepler family moves to nearby Leonberg, in the Lutheran territory of Württemberg.

  3. 1578

    Johannes Kepler enters the local Latin school.

  4. 1579

    The family moves to Ellmendingen in Baden.

  5. 1583

    Johannes Kepler returns to Leonberg and passes a scholarship exam in Stuttgart.

  6. 1584

    Johannes enters the elite boarding school in Adelberg.

  7. 1586

    He changes to the elite boarding school in Maulbronn.

  8. 1589

    Johannes inscribes himself at Tübingen University.

  9. 1590

    His father Heinrich dies.

  10. 1591

    He receives his first degree and remains in Tübingen to study theology.

  11. 1594

    Johannes Kepler starts teaching mathematics teacher at the Protestant school for aristocratic sons.

  12. 1596

    Kepler publishes his first book, the ‘Cosmographical Mystery',Mysterium.

  13. 1597

    He marries the Lutheran Barbara Müller.

  14. 1598-1600

    Johannes and Barbara are forced to leave Graz in October 1600.

  15. 1600

    Johannes Kepler collaborates with Tycho Brahe.

  16. 1601

    Publishes Apologia Tychonis contra Ursum.

  17. 1601

    Tycho dies, and Rudolf II appoints Kepler as Imperial Mathematician.

  18. 1602

    birth of his daughter Susanna.

  19. 1604

    Publishes his treatise Astronomia pars optica.

  20. 1606

    Publication of De Stella Nova (On the New Star).

  21. 1607

    birth of his son Ludwig.

  22. 1609

    Johannes Kepler travels to Württemberg; publishes the ‘New Astronomy’, Astronomia Nova; and a treatise on astrology, Tertius interveniens.

  23. 1610

    He responds to Galileo´s discoveries in his Dissertatio cum nuncio sidereo.

  24. 1611

    Barbara Müller dies; publishes Dioptrice.

  25. 1612

    Rudolf II dies.

  26. 1612

    Johannes Kepler has to leave Prague with his children because of the Counter-Reformation and finds a new position as mathematician for the Inner Austrian Estates in Linz.

  27. 1613

    He marries his second wife, Susanna Reuttinger.

  28. 1615

    Katharina Kepler is accused of witchcraft.

  29. 1617

    Johannes Kepler travels to Württemberg to help his mother.

  30. 1617-19

    Ephemerides Novae.

  31. 1618

    Beginning of the Thirty Years´ War; Kepler begins to publish his textbook Epitome Astronomiae Copernicanae.

  32. 1619

    Publishes his major work ‘Harmonies of the World’, Harmonices Mundi.

  33. 1620

    Johannes Kepler travels to Württemberg to defend his mother.

Cast & Creative

The People behind the Opera

Professor Ulinka Rublack

Author of The Astronomer & the Witch

Tim Watts

Music / Libretto

Aura Satz

Film Elements

William Ashford


Graham Walker



  • Katharina Kepler Cerys Purser (Mezzo-soprano)
  • Johannes Kepler Theodore Platt (bass-baritone)
  • Einhorn/Magistrate Matt Wilkinson (baritone)
  • Daemon Hugh Cutting (counter-tenor)


  • Schoolmaster/Gabelkhover Michael Bell (tenor)
  • Ursula Reinbold Alice Webster (alto)
  • Dorothea Klebl Carys Brown (soprano)
  • Young Johannes Jacob Fitzgerald


Extracts from Johannes Kepler’s legal defence of his mother, translated for the first time into English by Pamela Selwyn, with generous support of St John’s College. For the context of his defence see Ulinka Rublack, The Astronomer & the Witch, Oxford University Press, chs 11 & 12. The document has been cut to make it more readable for non-specialists: a scholarly edition of the full document and its legal citations is in progress. The purpose of this resource is to document in English the intensity of Kepler’s involvement in the trial and how he applied his ability to refute opponents in scientific arguments and argue for fact based procedure to legal proceedings in which his mother’s life and own reputation were at stake.
Ulinka Rublack

Read extracts from Johannes Kepler’s legal defence. (PDF)


For talks at schools and communities about the project in relation to the German Reformation, Johannes Kepler and the history of women and old age please contact Ulinka at ucr10@cam.ac.uk