The risky business of making predictions in the late medieval world

In the late medieval world, a new "science" appeared - astrology, which at the time was done concurrently with astronomy. During this period telescopes are getting more powerful, the movement of the planets and stars was known to be predictable and people start wondering whether it all meant something. Ideas from India were seeping into the west about how the stars could predict your future, and naturally Kings started employing expensive personal astrologers to make predictions about how their reigns would proceed. It was the late medieval version of opinion polls that try to predict elections.

But predictions were a dangerous business.

In the mid 1440's, Henry VI (who had bouts of madness and who tended to hide when there was a war on) executed two English astrologers for treason. Their crime? They had predicted that he would die a violent death.

As it happens they were right - Henry VI was defeated by the House of York, imprisoned in the Tower of London, and then murdered on the orders of Edward IV, who was re-crowned the day after Henry VI's death.

But astrologers took note - being right is no use if you are executed for your predictions.

The next astrologer to make a prediction was an Italian, Gulielmus Parronus Placentinus, known as William Parron in England, who was hired by Henry Tudor to make a prediction about his son Henry (who would go on to become Henry VIII). Henry Tudor was anxious - his eldest son Arthur had died the year before, and Henry was his only remaining son.

Parron produced a magnificent gold-leaf illuminated horoscope:

The predictions were equally magnificent. He predicted that the young Henry would marry well, would have many male heirs and would defend the church.

Well... Henry VIII married Catherine of Aragon (the daughter of Ferdinand and Isabella of Spain), so he definitely married well. But after about 20 years with no male heir, Henry divorced her, and then went on to marry five more times, (beheading two wives in the process). He managed to father just one sickly son, who became the boy king Edward VI.

As for defending the church - part of the prediction is true - after Martin Luther came on the scene, Henry VIII wrote an ardent pamphlete denouncing Luther and his ideas, for which he got rewarded by the Pope with the title "Defender of the Faith". Alas, within five years he had broken from Rome and set up the Church of England with himself as head. But predictably he kept the title "defender of the faith" and the current monarch still has this on her coins.

As for William Parron, he made one more prediction: he predicted Henry Tudor's beloved wife Elizabeth of York would live to her 80's. Alas she died only a couple of months after the prediction, aged just 37. Parron high-tailed it back to Italy, which was just as well, because if he'd remained in England he'd have been executed by Henry VIII for getting the predictions about male heirs so wrong. In fairness to William Parron, he probably knew his cheery happy predictions were complete bunk - he was just protecting himself by telling the client what they wanted to hear.