The Taittiriya Upanishad is associated with the Taittiriya school of the Yajurveda. It figures as number 7 in the Muktika canon of 108 Upanishads. It belongs to the Taittiriya recension of the Yajurveda and is constituted by the seventh, eighth and ninth chapters of Taittiriya Aranyaka. The tenth chapter of the same Aranyaka is the Mahanarayana Upanishad.
The Taittiriya Upanishad describes the various degrees of happiness enjoyed by the different beings in creation.
The text of the Taittriya Upanishad is a compilation of the late Vedic, pre-Buddhist genre. The date of composition is not known but is considered to be circa VI or V century BCE. Shankara's commentary dates from some twelve to thirteen centuries later. Shankara's commentary has influenced much of the subsequent interpretation of the meaning of the Taittiriya Upanishad. It is considered likely that texts such as the Upanishads were composed by groups of pandits and then amended over time. This, however, was not the view of Shankara. For him, as for certain contemporary brahmins and Hindus, the Taittiriya Upanishad and the Veda as a whole are not human compositions.
The Taittiriya Upanishad and Shankara's commentary are classics of Sanskrit literature. Along with other ancient Upanishad, they have been important sources of religion in India for more than two thousand years. The two texts have been instrumental in the spread of Vedanta. Parts of the Taittiriya Upanishad were translated into European languages as early as the XVII century. Since the end of the XIX century, the Taittirya Upanishad has been translated many times into European and other Indian languages.
The Taittiriya Upanishad is divided into three sections or vallis, the Siksha Valli, the Brahmananda Valli and the Bhrigu Valli. Each Valli further subdivided into anuvakas or verses.