The First Decan of Gemini

This is the first ten-degree segment of Gemini, the mutable air sign, spanning 0 to 10 degrees. Its ruler in the Chaldean order of faces is Jupiter, reached by continuing the sequence of the seven planets around the wheel of thirty-six decans. The decans are the most ancient stratum of the tradition, beginning as Egyptian stars whose risings marked the ten-day weeks of the year and were absorbed into the Greek zodiac as ten-degree subdivisions only in the last centuries BCE.

The Golden Dawn of 1888 assigned the thirty-six minor arcana to the decans in zodiacal order; this segment bears the Eight of Swords, titled Interference or Shortened Force, its Jupiter-in-Gemini planet taken from the face ruler, Jupiter in its detriment here, which suits the card's theme of restriction. The tarot correspondence is a modern overlay laid over the far older decan scheme, not part of the Egyptian or Hellenistic material.