From the hymns and verses about marriage in the Vedas, we learn that mature individuals were considered ready for marriage after puberty. In subsequent times however, brides were married even in childhood, perhaps due to a series of foreign invasions in North India. In an attempt to provide security their women from the invaders, early marriages became the norm. According to the scriptures of Manu, divorce and remarriage were not permitted. Most references to marriage in the ancient texts suggest that the Aryans were monogamous. However, some references to polygamy and polyandry have been found in the Hindu epic of Mahabharata.
See: Wife of Five Husbands -- The story of Draupadi through the works of great artists
See: Gandhi's memories on his wedding day
In medieval India, the marriage was compulsory for all the girls except for those opted asceticism. Brahmin girls were married between ages eight and ten from sixth or century onwards up to the modern times. Polygamy was permitted to all who could afford, and it was especially popular among Kshatriyas for political reasons. According to the Manasollasa, the king should marry a Kshatria girl of noble birth for a chief queen though he is permitted to have Vaishya or Shudra wives for pleasure.
See: Status of Women in Medieval India
Today, in India both divorce and remarriage are completely legal, whereas polygamy and polyandry are both criminal offences for Hindus, punishable by law. The Islamic personal law of Sheriat allows up to four wives for a man, and it is legal for a Muslim to have multiple wives in India.