The Middle Way of the Buddha

Beneath the Bodhi tree the future-buddha entered four subsequent states of meditation, and from these, he remembered his previous lives and gained understanding of the processes of Samsara that all forms of life are subject to. He saw that the cause of rebirth was ignorance which would only cease when the need for sense-pleasures were quenched. As his ignorance of the truth was dispelled he was set free, and seeing things as they truly are, he became an enlightened being. A Buddha.

The Bodhisattva Avalokiteshvara (Chenrezig)

The Bodhisattva Avalokiteshvara (Tibet: Chenrezig) vowed that he would not enter Nirvana until all beings had achieved liberation from the wheel of Samsara. He visited the three lowest realms of temporal existence and liberated many beings.
From the top of Mount (Su)meru, (the Axis-Mundi in Buddhist cosmology), he surveyed the ever-revolving universe and discovered that the three realms were once again filled with unending suffering. Avalokiteshvara, reflecting upon his vow, perceived that the task was impossible, and shattered into a thousand pieces.

The Buddhas restored Avalokiteshvara, equipping him with a thousand arms (an eye in every palm), and a multitude of heads, including a head of wrath. It is also said that when the Bodhisattva shattered, his new bodily form sprang into existence, better equipping him for the task of liberation.

Again, we are told, that Avalokiteshvara wept for all beings trapped within the wheel of ever-becoming, and from his tears, the Bodhisattva Tara was born, who is also his consort.