The treaty between Hitties and Mitannis dating to 1400 BC refers to Indra, Mitra, Varuna and Nasatya and curiously omits Agni and Soma - the important gods in Rig Veda.
The earliest Aryans lived in the region of E Afghanistan, NWFP, Punjab and fringes of W UP. Afghan R. Kubah and some other rivers are also mentioned in Rig Veda. Yamuna is referred to as twin of Ganga and Sutlej was associated with Beas - so neither were tributaries of Saraswati. They chose Punjab plains because they were now semi arid (due to climate change) and ideal for pastoral activities.
The river Saraswati is identified as R. Harakhwati or the present R. Helmand flowing in Afghanistan. The name Saraswati was transfered from here to India.
In the Later Vedic Age, they moved to doab region. The 10 tribes battle mentioned in Rigveda talks about some tribes (Agra, Yakshu, Shigru) which resided in the doab region. The Kurus occupied Delhi and the upper portion of the doab, the Panchala occupied middle doab. In W UP, they came up against OCP cultures.
The Panchala kingdom consisted of modern districts of Barely, Badaun and Farukhabad.
Towards the end of later Vedic age, they moved further east into E UP and N Bihar. Here they had to fight people using “black and red” pottery.
We know about this expansion in the later vedic period because the PGW sites excavated show a thickness of 1 to 3 meters indicating a settlement of 1 to 3 centuries and were not preceded by any habitation.
Economic Life
Early Vedic Age
They knew about agriculture, sowing, threshing, ploughing etc. But perhaps they used it only to grow fodder and were primarily pastoralists.
Later Vedic Age
The importance of agriculture grew so much that even kings didn’t hesitate in taking to plough. Eg. Janak and Balram. It was only later that agriculture came to be banned for higher varnas as its relative importance diminished and urbanization grew.
Politico-admin Life
Early Vedic Age
The head of a large pastoral ground was called vrajapati and he led kulapas (head of family) and graminis (head of fighting hordes) into the battle.
In the beginning, the gramini was just the head of a small tribal fighting unit. But as the unit settled, he became the head of the village and in course of time, became identical to vrajapati.
By and large it was a tribal form of government with strong militaristic elements. The civil character of the administration was missing because people were constantly moving as pastoral nomads.
Social Life
Evolution of Varna System
The term “vaishya” emerges from the vis or the mass of tribal people. Vis was the unit above “gram” and below “jana”.
The unequal division of war booty (with more going to the chief) and influence of religion / knowledge led to the stratification of the society into warriors, priests and rest (vis).
Women
In vedic age, the widow merely had to do a symbolic self immolation act at the death of her husband and it may have been a sign of status. Later on this was cited as the origin of sati with some tweaking of the practice in the religious texts.
Things had not settled down yet. There are many variants of marriages among pandavas only - endogamy, monogamy, polygamy, polyandry and cousin marriage (Arjun and Subhadra).
Education
The method of grammar and memorization of vedas was not simple and was fine tuned to making the composition almost unalterable (hymns had to be uttered in the right manner) and thus contributing to the supremacy of brahmans.
Education was open to only twice born and the curriculum was such that it was useful only for brahmans. Hence the supremacy of brahmans.
After Life Philosophy
Life after death was envisaged in terms of either punishment (you go to the house of clay) or reward (you go to the world of fathers). The idea of transmigration of soul was initially vague and was developed only later.
Upanishads encouraged the philosophy that souls were reborn into a life of sorrow or joy depending upon their deeds in the previous life and nothing could be changed now. This was then fitted into the caste hierarchy (higher caste means good deeds and lower caste means bad deeds). Upanishads also encouraged renunciation.
Sacrifices as Ritual and Social Exchange
There were occasions when the bards composed eulogies on the exploits of the chiefs and were rewarded with gifts. Gradually it became ritualized with hymns and elaborate sacrifices coming up to bestow legitimacy to the king in exchange for gifts. Gradually the priests began to confer divinity on the kings by the rituals. Sacrifices thus became an instrument of a power struggle between the king and the priest - with the priest eventually winning. These ceremonies initially began to enhance the status of the king but gradually became necessary for him to claim any legitimacy.
In these ceremonies he was supposed to donate all his wealth - either in the preparation of the sacrifice, or at the end of the sacrifice among the brahmans and other people (including craftsmen) and whatever remained had to be destroyed. This donation naturally kept a check on the wealth of the king and hence large states couldn’t come up and thus helped in maintaining the supremacy of the brahmans. Further, it was held that such donation was a way of earning even more wealth and thus legitimized the extraction of even more wealth from the vis by the king (hence the statement - the king (later replaced by kshatriya) eats the vis). Only later on when the agriculture production became so much that it was not possible to exhaust the wealth in the sacrifice that the kings were able to accumulate wealth and large kingdoms began to be founded.
This situation led to a reaction of some kshatriyas against the brahmans. Thus it comes as no surprise that the founders of Jainism and Buddhism were both kshatriyas or the ideas in the upanishads questioning the sacrifices all came from kshatriyas. Also the republics were controlled by kshatriyas only who didn’t confer to the brahmanical traditions and rituals and in turn were condemned by the brahmans (who championed the cause of monarchy).
This was extended to others as well and the patron of the sacrifice was now supposed to give a dakshina. The status of the patron depended upon how elaborate sacrifices he conducts and how much dakshina he gives. Soon it was held that a fraction of the benefit from the sacrifice also accrues to the patron. Any kind of material benefit (like property, son etc.) had to be prayed for and this further increased the power of brahmans.
Gradually even more spectacular sacrifices were evolved and now only the higher castes could participate in them. Thus sacrifices worked to reinforce the societal divisions. RItuals also meant a redistribution of resources and thus contributed to social inequalities.
As the sacrifices began to grow more elaborate, priests had to specialize in certain function and this led to creation of classes among the priests as well.
The worship of agni and soma were central to Indian and Iranian religions. Vedic sacrifices also produced the knowledge of mathematics and anatomy. Also the increased importance of agni meant that instead of burials, dead began to be cremated.
The dasas were ridiculed in the vedas for not practicing rituals and instead practicing fertility cults. The growing complexities and exclusions of the rituals finally led to alternate philosophies and sects.