Originally, before human beings really existed, the entire zodiac belonged to and was the responsibility of only the Sun and Moon. The Sun, specifically, made his home in Leo and cultivated it. The Moon made her palace in Cancer. So only two of the zodiac signs had really been developed at this stage of evolution.
But the smartest and most exchange oriented of all the planets, Mercury, got an idea. He went to the Sun and Moon and proposed a deal, “If you give me some space, I will take the responsibility for it off your hands.” The Sun and Moon agreed. They gave Mercury the space on either side of their own. The Sun gave Virgo to Mercury, the sign next to his own Leo. The Moon gave Gemini, the sign next to her own Cancer.
Mercury and Venus are always close and are good friends. So Mercury went quickly to her and told her the amazing news. She came back with Mercury to the Sun and Moon and said, “I too will take good care of the space you give me, and thus lessen the burden of your responsibilities.” Agreeing, the Sun gave Libra to Venus, the space just after Virgo – the closest available plot to his own Leo. In the same fashion, the Moon granted Taurus to Venus, the space just outside of Gemini – the closest remaining area to her own Cancer.
A few days later, Mars came to know of this and became angry. He went to the Sun and Moon saying, “I am always loyal to you! But you have given land to a poet and an artists before giving it to your loyal agent!?” The Sun and Moon apologized by giving to Mars the closest space still available: The Moon thus gave Aries to Mars and the Sun gave him Scorpio.
Seeing Mars come into the picture, Venus could easily foresee the future. He was going to try and conquer the whole remaining half of the zodiac if nobody else claimed it. She went to Jupiter and Saturn but they were uninterested in asking the Sun and Moon for material property. So she returned to the luminaries and said, “My dear Sun and Moon, Jupiter is too modest and unconcerned with material things. He will never ask you for any space to cultivate, he will never ask for any land. Still, he is your guru! Your revered teacher! It would be a grave insult to let him remain without any property, while the rest of us enjoy our own space! We will all suffer negative karma if we let this insult exist.”
The Sun and Moon then went to Jupiter and requested him to take possession of the next available space. Thus the Moon gave Pisces to Jupiter, and the Sun gave him Sagittarius.
Venus, who was present, then had the chance to fulfill her ultimate design – the gifting of land to her dear friend, the unloved Saturn. She pointed to him brooding off in the distance as usual. “Just see, Saturn broods in the distance. His anger will be great, and that will not be good. There are only two plots left and they are already the furthest from your own. He is already there by default, as well. So why be seen as generous and officially give him that space?”
They agreed. The Sun and Moon reluctantly approached Saturn and said, “We are giving you full possession of this area of space, Saturn. It is yours to develop and cultivate as you see fit. The Sun granted him Capricorn, and the Moon gave him Aquarius.”
Thus of all the wild stars in the sky, a narrow band called the zodiac became civilized and developed as a result of being occupied by “people” – the planets. This area became divided into 12 plots because the original owners, the Sun and Moon had a 12-based relationship to it: As the Sun would go around the entire zodiac one time and created a year, the Moon would become full 12 times, creating 12 months. And thus the zodiac divided into 12 distinct plots – one for each full moon. The Sun took special ownership of Leo and the Moon of Cancer. And then, beginning with Mercury the planets came to ask for (or were given) their own plots to be responsible for cultivating and civilizing according to their own natural characters.
This incident took place in cosmic history before the creation of the 8th and 9th planets: Rahu and Ketu. Therefore these two do not own any of the zodiac signs.