The Third Decan of Cancer

This is the third ten-degree segment of Cancer, the cardinal water sign, spanning 20 to 30 degrees. Its ruler in the Chaldean order of faces is the Moon, which rules Cancer itself, so here the face ruler and the sign's own ruler coincide. The decan is the oldest layer of astrology, the thirty-six having begun as Egyptian star groups used to divide the year and the night, absorbed into the zodiac as ten-degree arcs only in the last centuries BCE.

The Golden Dawn, from 1888, mapped the numbered minor cards onto the decans in zodiacal order; this segment carries the Four of Cups, to which they gave the title Luxury or Blended Pleasure, its Moon-in-Cancer attribution taken from the face ruler, the Moon at home in its own sign giving the card its heavy, sated, slightly stagnant water. That tarot layer is a modern Western overlay on the ancient decan scheme rather than part of the inherited tradition.