Combination or Union of one or more is called Yoga. This word Yoga is arrived from the root YUJIR means Yoge. In Astrological science, yoga means union of planets. Various planetary combination in various signs get united in various bhavas. The Doctrine of Karma and Astrology has a close relationship. The soul out of its deed for enjoying the fruits either happiness or sorrow or grief in a fixed time, places and family by taking new birth is described in the doctrine of Karma. The same is picturised indicating its time in the science of astrology as Fate. It also determines creation, state and destruction. If it is closely observed, every one will understand that the probable experience of happiness and sorrow form the life and the longevity. Of the two, longevity is most important. The length of the Longevity is directed in the form of yogas existing in the Birth chart at the time of Birth.
Pancha Maha Purusha Yoga :
Ruchaka badraka hamsaka malavah
sa sasaka iti panchacha keerthitah
kshiti sutadishu tan kamaso vadet
Ruchaka, Badra, Hamsa, Malava and Sasa yogas are called as Pancha Maha Purusha Yogas. These yogas occur with the planets Mars, Mercury, Jupiter, Venus and Saturn. This should be confirmed with planets be in Quadrents (1-4-7-10) either from the Ascendent or Moon Ascendent. Also these quadrents myst be their own or in exalted sign.
Jathaga Parijatha describes as:
moola trikona nija tunga grihopayata
bhoymajna jeevasita nhanusuta balishtaah
kendrasthita yadi yada ruchi bhadra hamsa
malavya charu sasa yoga kaara bhavanthi
This is was also opined by Varahamihira in Brihat Samhita as :
Taragrahair balayutaih swakshetra sochchagais chathushta yagaih
pancha purushaah prasasta jayante tanaham vakshaye
When the 5 planets possess strength in Own / Exalted houses, and if those signs happens to be in the quadrent from Ascendant / Moon Ascendant, then Panchamahapurusha Yoga is formed. Most important is these 5 planets should have attained the strength in Shadbala.