The three children, born courtesy Vyasa, were brought up by Bheeshma. Dhritarashtra the first born was anointed as the Yuvaraja, Pandu skilled in the use of weapons was appointed the commander of the army and Vidura as the minister to the king. The Kuru trio ruled as a team.
(The epic which in English is termed a mythology is also full of myths! Dhritarashtra and Pandu are called Kuru vamshi's only because of an accepted convention, they do not carry any DNA of the Kuru's as a matter of fact. Two of them are children of Kashi princesses and a Rishi and it is said that one should not seek the Rishi moola or origin. Vidura is not even a Kshatriya! The much flaunted Khandhaan or vamsha, grist of most Bollywood movies is obviously very tenuous here! )
In time, Dhritarashtra was married to Gandhari in Hastinapura. She travelled from Ghandhara with her brother Sakuni. Ghandhari covered her eyes with a peice of silk to be one with her husband who was blind. A tremendous self-sacrifice and a noble gesture. She did not want to see if her husband could not! Pandu who participated in a swayamvara was chosen by the beautiful Madri for is noble looks. Thus the great Kuru house had two wonderful brides.
(It is no surprise that there was no talk of finding a bride for the wise Vidura. He was fortunate that he was brought up in the palace. Today, in all likelihood, both Vidura and his mother would have been sent back to the village she came from. No talk of caste here!
Ghandari is described as gentle and beautiful! She also proved to be very innocent. Her decision meant 'blind leading the blind' as both she and her husband became dependent on others. We can only speculate on the consequences of such a situation, especially in the upbringing of their children!)