Mesha lagna · vimshottari
The Mercury Mahadasha for Aries Ascendant
17 years · Mercury rules the 3rd and 6th
The Parashari way to read a mahadasha for a given ascendant starts with the houses its lord holds. For Aries ascendant Mercury rules the 3rd (Gemini) and the 6th (Virgo), so for Aries the 17-year Mercury mahadasha carries both an upachaya house and a dusthana and an upachaya house.
Counted from Aries, Mercury is exalted in the 6th (Virgo) and debilitated in the 12th (Pisces). Mars, Aries’s lagna lord, counts Mercury an enemy; Mercury counts Mars neutral. Mercury’s own nakshatras fall in Ashlesha (the 4th), Jyeshtha (the 8th) and Revati (the 12th) for Aries ascendant, which is where a birth that opens in the Mercury mahadasha has its Moon.
The Nine Sub-Periods, by Lordship for Aries
| # | Antardasha | Length (classical) | Its lord rules, for Aries |
|---|---|---|---|
| 1 | Mercury–Mercury | 2 years 4 months 27 days | the 3rd and the 6th |
| 2 | Mercury–Ketu | 11 months 27 days | no house |
| 3 | Mercury–Venus | 2 years 10 months | the 2nd and the 7th |
| 4 | Mercury–Sun | 10 months 6 days | the 5th |
| 5 | Mercury–Moon | 1 year 5 months | the 4th |
| 6 | Mercury–Mars | 11 months 27 days | the 1st and the 8th |
| 7 | Mercury–Rahu | 2 years 6 months 18 days | no house |
| 8 | Mercury–Jupiter | 2 years 3 months 6 days | the 9th and the 12th |
| 9 | Mercury–Saturn | 2 years 8 months 9 days | the 10th and the 11th |
For Aries ascendant, three of the Mercury mahadasha’s sub-periods belong to lords of a dusthana (the 6th, 8th or 12th): Mercury–Mercury, Mercury–Mars and Mercury–Jupiter, and two to lords of a trikona other than the 1st: Mercury–Sun and Mercury–Jupiter. The sub-period of Mars, Aries’s lagna lord, is Mercury–Mars, the sixth of nine, 11 months 27 days long. Counted in time, sub-periods whose lords hold a dusthana for Aries take 5 years 8 months (33%) of the Mercury mahadasha’s 17 years, and those whose lords hold a trikona other than the 1st take 3 years 1 month 12 days (18%); a lord holding both is counted in both. In the Mercury mahadasha for Aries, the Rahu and Ketu sub-periods are read through their dispositors in the chart, since neither node rules a house.
For an Aries-rising chart this is the frame of the Mercury mahadasha, not a forecast: where Mercury and each sub-period lord actually sit, and their dignity there, decide what it comes to, and this page cannot know either.
Related
For Aries or any other ascendant, the Mercury mahadasha’s sub-period arithmetic, with the nine pratyantars of each, is on the Mercury mahadasha table; the Aries chart house by house on the Aries ascendant page. How the Mercury mahadasha is read in general is in our Mercury mahadasha article, and the system in Vimshottari dasha explained.