Complex sentence: Baltistan is a self-governing territory that was established as a single administrative unit in 1970, formed by the amalgamation of the Gilgit Agency, the Baltistan region and the former princely states of Hunza and Nagar.
Split into simpler sentences: Baltistan is a self-governing territory, which was established as a single administrative unit in 1970. It was formed by the amalgamation of the former Gilgit Agency, the Baltistan District, and the former hill states of Hunza and Nagar.