Aries first decan

Your two rulers

Triplicity

Mars, reached through Aries. This scheme walks the three signs of your element in order, so a Aries decan is coloured by Aries without becoming it.

Chaldean

Mars, from the unbroken run of seven visible planets that starts at Mars in the first decan of Aries and never resets.

Both schemes land on Mars here, which happens often enough to be unremarkable and is not evidence that either is the right one.

You have two rulers, not one, because two schemes exist and they disagree. Both are shown here and neither is blended into the other. The triplicity scheme walks the three signs of your decan's element in order, so the Aries decans are ruled through Aries, Leo and Sagittarius. The Chaldean scheme runs one unbroken cycle of the seven visible planets, starting at Mars in the first decan of Aries and never resetting when a sign ends. They agree sometimes and part company often. If someone tells you there is one correct ruler for your decan, they are picking a lineage without telling you they picked.

The other two Aries decans

• second decan10° to 20° of Aries · Sun · Sun
• third decan20° to 30° of Aries · Jupiter · Venus

Mars also rules 5 other decans in the Chaldean run, which is what an unbroken cycle of seven across thirty-six bands produces.

What this calculation assumes

version

asternym-western-advanced-v1

zodiac

Tropical

decanSpan

Exactly 10°, three to a sign, thirty-six in all

decanRulers

Two schemes, both shown and never blended: the triplicity scheme walks the three signs of the element, and the Chaldean scheme runs one unbroken cycle of the seven visible planets from Aries I, never resetting at a sign boundary

decanGuardians

Not computed. The guardian-deity decans circulating online are a modern invention with no fixed date table behind them