The Kumbha Mela is primarily a North Indian observance. Though, the south does have a similar gathering at Kumbakonam at the Mahamaham tank, every 12 years, in the month of Magha, shortly after the sun enters the zodiac of Capricorn (Makara). But here, there is no river involved, certainly not the Ganga, the traditional marker of Aryavarta.
Prayag means a river confluence. There are five prayags in Uttarakhand, where the Alaknanda River is joined by different streams from the Himalayas. The last of these is the Bhagirathi River, which joins at Devprayag, where it is renamed the Ganga. At Haridwar, the Ganga descends from the mountains and enters the plains, making it a sacred site. The term ‘Kumbh Melaʼ was originally applied only to this gathering every 12 years at Haridwar, when Jupiter enters Aquarius (Kumbha Rashi). Once every 144 years (12X12=144), it would be referred to as the Maha Kumbh Mela.
Haridwar was once called Gangadvar, and as per the Mahabharata, this is the site linked to the earliest confrontation of Daksha, the Vedic priest, and Shiva, the ash-smeared god of the Naga sadhus. Later, it came to symbolise the amrita (nectar of immortality) that was churned from the ocean of milk. The story of the churning of the ocean (Samudra Manthan) is absent from Vedic scriptures and appears only in the Mahabharata. Also, in the Mahabharata (100 BC), Brihaspati, priest in Rig Veda (1500 BC), is identified with Jupiter for the first time.
As we move south, at the spot where the Yamuna meets the Ganga, the Magh Mela was held annually in the month following Makar Sankranti, when the sun enters Capricorn. This site was renowned for being where the Jain Tirthankara of this era, Rishabh Nath, delivered his first sermon, the Samavasarana. It is also closely linked to the Buddhaʼs first sermon. The Magh Mela, which took place when Jupiter entered Taurus (Rishabha), gained significance over time. It was renamed as another Kumbh Mela much later, after 1857.
Even further south, in the Malwa plateau, on the banks of the Shipra River, a rain-fed tributary of the Chambal, which in turn flows north to join the Ganga, lies the city of Ujjain. Here stands the Mahakaleshwar temple, and is the site marking the Tropic of Cancer. This marks the lowermost limit of Aryavarta traditionally, as south of this spot, the shadow falls to the south on some days of the year. In Aryavarta, the shadow always falls to the north.
Beyond the Vindhyas, on the banks of the Godavari River stands the temple of Trimbakeshwar. This is below Tropic of Cancer, so way below the original Aryavarta. When Jupiter enters the constellation of Leo, the Kumbh Mela is held in both Ujjain and Nashik. It is traditionally called Simhastha though, named after the Simha Rashi (Leo zodiac). The specific location depends on the position of the sun: when it is in Cancer (Karka), the mela takes place in Nashik; when it is in Aries (Mesha), it takes place in Ujjain. These are roughly around the summer solstice and spring equinox.
If one observes these gatherings, they are linked to rivers, they are linked to stars and planets, they are roughly linked to winter solstice, spring equinox, summer solstice, and rarely on autumn equinox, so essentially the brighter half of the year is linked to Devas. In 500 AD, Uttarayana began (winter solstice) at Makar Sankranti (movement of sun into Capricorn) i.e. January 14. Now it happens on December 22. The deviation of three weeks is because the original calculation with zodiac was made in 500 AD. Since then, the zodiac signs have shifted as per precession of equinoxes, a celestial phenomenon not observed by astronomers then.
The zodiac itself is not mentioned in Vedic scriptures or the Mahabharata. The idea entered India around 500 AD, and was popularised by Aryabhatta in Ujjain. This is the time when the Brahmins were still located in North India, and their migration to the south had just begun. Brahmadeya land grants slowly start appearing in Gujarat and Odisha. Brahmin land grants appear further south only after 800 AD.
So, all Kumbha Mela sites are linked to Aryavarta, north of the Tropic of Cancer, and related to the Ganga and its tributaries. Nashik, on the bank of the Godavari, is exceptional as it is in the south, even below the Vindhya mountains and the Narmada River. This is not surprising as the gathering began only in the 17th century, when Maratha power was rising and it was challenging Mughal authority, when memories of the old boundaries of Aryavarta were forgotten and Manusmriti told everyone that Aryavarta extended from Himalayas to the seas.
