Quick answer: William Lilly (1602 to 1681) was England's most famous astrologer, nicknamed the English Merlin. His Christian Astrology (1647) was the first major astrology textbook printed in English rather than Latin, putting the art within reach of ordinary readers. It is best remembered for codifying horary astrology, the practice of answering a specific question from a chart cast for the moment it is asked.
Most astrology before the seventeenth century was locked away in Latin, accessible only to scholars. One book changed that for English readers, and the man who wrote it still shapes how traditional astrology is taught today.
Who William Lilly Was
William Lilly lived from 1602 to 1681 and became the most famous astrologer in England, widely nicknamed the English Merlin. He rose to prominence during the turbulent years of the English Civil War, a period when public appetite for predictions about the conflict and the fortunes of the nation ran very high.
Lilly was not only a writer but a working practitioner who answered questions for clients and produced popular almanacs year after year. Those almanacs reached a wide audience and made his name a household word in a way few astrologers ever achieve.
The Book That Opened the Door
In 1647 Lilly published Christian Astrology, the first major astrology textbook to be printed in English rather than Latin. That single decision mattered enormously: it took a technical art that had lived in scholarly Latin and placed it within reach of any literate reader.
A note on the title. Christian Astrology reflects the language and culture of its era, not a religious doctrine built into the method. The astrology Lilly taught is technical and rule-based, and the title is best read as a marker of his time rather than a system of belief.
How Christian Astrology Codified Horary
The lasting contribution of Christian Astrology was the way it organized horary astrology. Horary answers a specific question by casting a chart for the exact moment the question is asked and understood, then reading that chart for the answer.
Lilly laid out the method with unusual clarity, and two ideas sit at its heart:
- Significators: each part of the question is assigned a planet or point, so the querent and the thing asked about are each represented in the chart.
- Perfection: the answer turns on whether the significators come together, by aspect or other means, which shows whether the matter "perfects" or comes to nothing.
Alongside horary, the book also covered natal work (reading the chart of a birth) and mundane astrology (reading charts for nations and events), making it a full course in the traditional art.
The Great Fire and Parliament
Lilly became famous for an image that appeared in a publication of 1651. After the Great Fire of London in 1666, that image was read by many as having foretold the disaster.
The episode had real consequences. Following the fire, Lilly was questioned by a parliamentary committee about the image and his apparent foreknowledge. He was not found to have caused the fire, and the story has lived on as one of the most striking moments in the history of astrology. It is a useful reminder that an image read after the fact can look prophetic in ways that were not obvious before.
Why Lilly Still Matters at AstroAk
What makes Lilly worth reading today is his clear, rule-based method. Horary in particular shows astrology working as a disciplined craft: significators are assigned by rule, and the verdict follows from whether the chart perfects, not from guesswork or mood.
That same traditional logic sits behind AstroAk's classical features, which apply rules rather than vague intuition. If you want to see traditional symbolism in a lighter daily form, the AstroAk daily horoscope reads the sky through that same inherited language, while the deeper rule-based techniques carry the spirit of what Lilly set down in 1647.
Frequently Asked Questions
Who was William Lilly?
William Lilly (1602 to 1681) was England's most famous astrologer, nicknamed the English Merlin. He worked through the English Civil War and published popular almanacs as well as his landmark textbook.
What is Christian Astrology by William Lilly?
It is Lilly's 1647 textbook, the first major astrology book printed in English rather than Latin. It is best known for codifying horary astrology, including the use of significators and perfection.
Did William Lilly predict the Great Fire of London?
He became famous for an image in a 1651 publication that was later read as foretelling the Great Fire of London in 1666, and he was questioned by a parliamentary committee afterward. Whether it was a genuine prediction remains a matter of historical debate.
