William Lilly’s “True” Birth Chart


The previous post about Lilly’s view of eclipses got me thinking about his birth chart. There has been controversy in the literature about the true natal chart of the famous 17th century astrologer William Lilly. A widely accepted birth chart for Lilly is the one published in London by Gadbury in his Collectio Genitorum of 1662 and apparently verified by several primary directions. Here is a photocopy of Gadbury’s version of Lilly’s birth chart:

Gadbury’s version of Lilly’s nativity is set for latitude 52n38 at 14h 8m of 30 April 1602 (OS), which converts to roughly 2:08 AM on 11 May 1692 in Diseworth, UK. The MC of this chart has a R.A. of 259d 37m. Regiomontanus Houses. The Ascendant has O.A. of 349:37.

Years ago Sue Ward published in the Astrological Association’s Journal a copy of the chart which Lilly had apparently rectified and used for himself. She had come across a reference to it in the autobiographical notes of Elias Ashmole and looked it up in the Ashmole’s Collection at the Bodleian Library. Here is a copy of Lilly’s personally rectified chart for himself from the Ashmole Collection:

Lilly’s Natal Chart, apparently used and rectified by Lilly himself, from the Ashmole Collection at the Bodleian Library. The MC of this chart is at R.A. 259d 36m, just one minute of arc different from that of the Gadbury chart above. It is cast for a latitude of 53n as opposed to 52n38 in the Gadbury chart. Regiomontanus Houses. The Ascendant has O.A. of 349:36.

The above two charts (Gadbury vs Lilly) are strikingly similar, so the reason for controversy is a bit hard to understand. It may have to do with the animosity between the two astrologers during their lifetimes. If we study these two natal charts for Lilly objectively, using modern planetary observations and computer calculations, we find that Gadbury was far more accurate than Lilly in the technical matter of drawing up the chart.

Because both charts were verified by several primary directions, we can assume that the R.A. of the MC is reasonably accurate. Lilly gives the MC a R.A. of 259:36 and Gadbury gives 259:37. For our purposes let’s work with an R.A. of 259:36:30 for the MC, the midpoint of the value in the two charts, and assume that this is a correct MC for the moment of Lilly’s birth.

Next we need to establish the coordinates of his birth place. Historical sources report that Lilly was born at what is now called Lilly’s Cottage at 54 Hall Gate in Diseworth, Leicestershire, UK. Checking in Google Maps, we find the coordinates of his birth to be 52n49 and 001w20, rounded to the nearest minute of arc:

Lilly was born at 54 Hall Gate in Diseworth. Google Maps gives the coordinates as 52.81663 and -1.33189, which are 52n49, 001w20 rounded to the nearest minute of arc.

Now we calculate a chart for May 11, 1602 (NS) at location 52n49, 001w20 with the MC at R.A. 259:36:30, and Regiomontanus Houses. Such a chart looks like this:

A very close modern approximation to William Lilly’s “true” birth chart, as verified by primary directions done by James Blackwel and by Lilly himself. Calculated with Solar Fire Deluxe.

In studying the above chart we can see that Gadbury was far more accurate than William Lilly in casting Lilly’s own birth chart in a manner consistent with modern scientific observations of planetary motions and the calculation of Regiomontanus Houses.

Here is another view of Lilly’s “true” natal chart for the midpoint between the Gadbury and Lilly/Ashmole charts, calculated with the program Regulus Platinum:

The above chart is an alternate view of Lilly’s “true” birth chart with MC at R.A. 259:36:38 and the Asc at O.A. 349:36:38, calculated in the program Regulus Platinum. This chart is at the midpoint of the one used by Lilly himself and the one published by Gadbury. Houses are Regiomontanus.



About Anthony Louis

Author of books about astrology and tarot, including TAROT PLAIN AND SIMPLE, HORARY ASTROLOGY, and THE ART OF FORECASTING WITH SOLAR RETURNS.
This entry was posted in Astrology and tagged , , , , , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s