Aries - Mar 21 - Apr 20:
Keyword: "I Am".
The nature of this zoidion is tropical and movable. By the medieval era, astrologers gave it the element of fire. The tropical signs are sometimes called movable because they are the initiators of the zodiac, where something new has begun. Of the parts of the body, it rules the head, "because a rams power is in the head" . It is the house of Mars, meaning that Mars does the administration of the duties for this place. Because this is the sign in which light first has victory over darkness, the Sun is said to be exalted in this sign, especially at about the 19th degree. This is because the daylight is more in abundance than darkness in the northern hemisphere this time of year. Exactly where this degree is, truly isn't known, because of the issue of precession of the equinoxes. Valens was said to have used a zodiac where 8 degrees of Aries was the vernal point. Others used 10 degrees of Aries as the vernal point. We also cannot say whether the zodiac they were using was tropical or sidereal.
Easter occurs this time of year after the first full Moon of a new moon in Aries. The waxing Moon was associated with an increase in evil and contrariety (like Plato's Other) and black magic. The waning Moon then, was a reprieve from evil, and gave power back to the Sun (Plato - Same). This became symbolic of the Son of Man and the resurrection, and of the renewal of life after a long winter. The key words "I am", (or "I am that I am") was one of the most important biblical phrases in the old testament during the age of Aries. The easter egg is also another symbol for the birth of a new potential. They are supposed to be hidden in darkness (symbolic of the mothers womb) and found in the daylight (potential realized). Despite the symbolism surrounding birth, this zoidion is not regarded as prolific (good for having children) in a physical sense, because of its choleric (medieval sources) temperment. The firey nature combined with a cardinal (or tropical, movable) nature makes for a very dynamic and powerful start. Because of its association with Mars and the Sun, it is a very masculine zoidion and is found to be prominently emphasized in the charts of leaders, warriors, rebels, pioneers and those with great audacity and courage. By comparison, Valens says:
"Those who are born in this zoidion in accordance with the rulership relation, then, will be bright, notable, commanding, just, with a hatred of knaves, free, authoritative, bold in purpose, braggarts, great-souled, inconstant ... When the rulers are well situated and testified to by benefics, the natives become kingly, powerful, and have the power of life and death."
More information on each of the planets in Aries: