Partisan Mahabharata?

Is history written by the victor, and hence really partial? 

Perhaps! Actually, no! For certain! 

All history is pretty-much written by the victors - either by commission (ex. Akbarnama) or indirectly (ex. Ashoka of the Mauryas through edicts attributed to him), so you essentially get the victor's standpoint and viewpoint and the vanquished party's achievements and/or legacy is completely lost or worse, eradicated. 

That brings us to one of the greatest epics and what Bharatiyas consider itihasa (history) - The Mahabharata. Is the Mahabharata partial to the victors? Does it extoll the Pandavas while pushing Kauravas to the depths of adharma? Perhaps we have missed out the legacy of the Kauravas because the author was partial to the Pandavas?

To examine this in detail, it is important to understand the family tree of the Kuru dynasty - post Shantanu (with whom the Mahabharata really begins) very clearly, and understand the biological bloodlines, the legal family bonds not withstanding. It will be clear why in a moment. 

For all practical purposes the Kauravas and Pandavas were cousins - sons of brothers Dhritarashtra and Pandu respectively - who shared the same father but had different mothers. What, though, of their biological bloodlines? Did they actually have paternal familial blood of the Kuru dynasty in them? What of the author of the Mahabharata itself? How, if at all, was he related to the main actors of the epic? When you start plotting these biological and legal bloodlines, a very complex picture arises:

First up, of course, is Bhishma, born from Shantanu and Ganga. Bhishma is both biologically and legally in the Kuru line.

Krishna Dwaipayana Vyasa, (or Vedavyasa) arises from a pre-marital association of Satyavati and the sage Parashara.

Meanwhile, Bhishma makes a vow of celibacy, and Shantanu marries Satyavati. Chitrangada and Vichitravirya arise from this union. Both Chitrangada and Vichitravirya are legally and biologically in the Kuru line. 

When Chitrangada dies early in life, Bhishma wins the princesses of Kashi - Amba, Ambika and Ambalika for Vichitravirya. Amba refuses to marry Vichitravirya, but Ambika and Ambalika do. Vichitravirya, however, has no heirs with Ambika and Ambalika and he too dies prematurely of disease. 

With Bhishma's vow of celibacy intractable, Satyavati convinces her other son - Vyasa - for a niyoga union with Ambika and Ambalika in order to produce legal heirs in the Kuru family. 

Side note: 

Niyoga

Niyoga is exclusively for the sake of praja utpatti or creation of progeny in a childless marriage or in the case of absence or death of the male partner, with the consent of the male partner (when alive) and/or his family. Sensual pleasure is actually cut out of the equation in niyoga following a specific process.

Niyoga was a recognized method of procreation during the age in question even if not quite a common or regular practice. 

Niyoga vs Adultery

Adultery is essentially two people - not married to each other - 'hooking up' for the sake of sensual pleasure, without the knowledge or consent of their legal partners or families. 

The legal lineage of the child born of niyoga is that of the legal husband (alive or dead) of the woman bearing the child(ren). The biological father of the child born of niyoga has no legal authority or obligation on the child or the mother.    

Out of the union of Ambika and Vedavyasa, Dhritarashtra is born - blind, since Ambika shuts her eyes to the sight of Vyasa. Likewise, Pandu is born out of the union of Ambalika and Vyasa - with some description of a shivering disease, since Ambalika was shivering (in fright?) at the sight of Vyasa. On a third attempt by Satyavati to produce a healthy heir in the Kuru family, Ambika and Ambalika defy the directive and send a dasi - a maid - in their stead and out of this union is born the wise Vidura. 

By this time, the legal heirs of the Kuru family are no longer have Kuru blood in them. They are in the blood line of Parashara-Vyasa.

Eventually, despite being the elder son, Dhritarashtra is pushed out of line of the Kuru throne of Hastinapura because of his blindness, in favour of Pandu. With Dhritarashtra eventually marrying Gandhari, Duryodhana and all Kauravas are legal Kuru heirs with their biological grandfather being Vyasa. 

On the other hand Pandu comes under a shaapa - a curse - that he shall be unable to experience sensual pleasure, and the moment he tries, it shall be followed by his death. Pandu abdicates his kingship of Hastinapura in favor of Dhritarashtra and retires to the forests with his wives Kunti and Madri. 

Pandu is desirous of producing heirs, but is unable to do so because of the curse he is under. The only option ends up being niyoga again, and in this case, Kunti has the secret to call the devatas - Yama, Vayu, and Indra - whom she calls upon to produce Yudhisthira, Bhima and Arjuna respectively. She passes the secret to call upon the Ashvini twins to Madri, who produces the twin Pandavas, Nakula and Sahadeva. It must be noted that despite their biological descent, the Pandavas are legally acknowledged Kuru family heirs and a question about this legality is never raised in the epic. 

Note: Yudhishthira is older than Duryodhana, and being the legal heir of the king who abdicated because of a curse, is legally the next in line to the throne of Hastinapura. Duryodhana, being the oldest son of the current reigning king also considers himself as the next in line to the throne of Hastinapura. This competition is essentially the root of the Mahabharata war

At this point, even Parashara-Vyasa's bloodline has stopped at Pandu in this branch of the Kuru family, with all of Pandu's legal sons being born of niyoga, and hence being biological sons of the devatas. 

Note: Kunti also has a premarital union with Surya (through the same secret gifted to her by Durvasa muni), of which is born Karna. Karna is biologically the son of Surya, but his legal status is that of a suta, since his adoptive father was one as well. 

Krishna Dwaipayana Vyasa, or Vedavyasa is the acknowledged original scribe of the Mahabharata - even if the version that we know today is as retold by the venerable Vaishampayana. At least one other version - that of Jaimini exists in part through other retellings (that of Lakshmisha in Kannada) and (at least the part that still exists) is found to be distinct from the Vaishampayana version in both style and content. It is clear that there were three other disciples of Vedavyasa, namely, Sumanta, Paila, Shuka, however, while it must be assumed that these three also retold the Mahabharata in their own way, those versions remain lost to us, as does most of Jaimini's. 

Ostensibly, even if the Mahabharata is essentially a fight between cousins for the right to succession, from Vyasa's personal standpoint, Duryodhana and Kauravas as his direct biological descendents with his own blood in them. The Pandavas, meanwhile, are not, even if their legal father is. 

If anything, Vyasa would, should be partial to the Kauravas - his own flesh and blood, but the fact that he isn't, the fact that he holds the Pandavas as upholders of dharma and Krishna as Vishnu himself is indicative of the fact that this particular itihasa is NOT a partisan tale.