Early Life

Sambhaji was born on 14th May 1647 at Fort Purander.  Sambhaji or Shambhu raje as he was fondly called, was the eldest son of the legendary maratha king, Ch.Shivaji Maharaj (Bhosale). Sambhajis mother was Saibai from the family of Nimbalkars of Phaltan. She died early (5th September 1659, at fort Rajgad) after a brief illness, leaving the young Sambhaji in the care of his grandmother Jijabai. 

Shivaji being away on his various campaigns and expeditions,  Sambhaji was raised by his grandmother and his stepmothers.
A very young Sambhaji was married to a minor, Jivubai (renamed , Yesubai) , the daughter of Pilajirao Shirke. It was a matrimonial alliance. Pilajirao was an powerful Deshmukh  from the Konkan region. He owed allegience to the court of Bijapur . However after marriage , Pilajirao provided Shivaji access to Konkan belt paving the way for his southern ambitions. 

Note: Incidently, Ch.Shivajis second wife Soyrabai (mother of Ch,Rajaram) was also from the house of the Shirkes.

Sambhaji was exposed to the cruelties of politics at a very young age. When Mirza Raje Jaisingh cornered Shivaji and forced on him a humiliating treaty at Purandar, a part of the agreement stipulated that young Sambhaji was to be kept as a collateral towards Shivajis satisfactory adherance to the agreement. Sambhaji was also to serve as a courtier in the mughal Viceroys camp at Aurangabad.
Later Sambhaji also came to be a part of Shivajis entourage to Agra and was subsequently confined there along with his father. When Shivaji escaped from Agra, Sambhaji was left behind in the care of some friendly brahmins (relatives of Moropant Pingale the Peshwa). A rumour was also floated that Sambhaji had died during his escape and at Rajgad even his obsequies were performed. This was ofcourse done to throw the Mughal search parties offguard. Sambhaji was sent back to Maharashtra much later, once the danger to his life had elapsed.