The brahmin varna described in the classical texts, including the Purusha Sukta hymn that derives the four varnas from the body of a cosmic being, is a single category in theory but has always been realised as a large number of distinct, often mutually exclusive regional communities in practice: the Namboothiris of Kerala, the Iyers and Iyengars of Tamil Nadu, the Saraswat brahmins of the western coast, and the Kashmiri Pandits of the Himalayan north, among many others, differ from each other in ritual practice, language, marriage custom and social history as much as they resemble each other in varna status, and marriage across these regional brahmin communities has historically been uncommon.
The modern history of one such community illustrates how much the general label can obscure: the Kashmiri Pandits, a small brahmin community distinct in language and custom from brahmin communities elsewhere in India, were displaced from the Kashmir Valley in large numbers amid the violence of the insurgency that began in 1989 and 1990, a documented exodus whose scale and causes remain a live and contested subject in Indian politics. Brahmin communities have also migrated well beyond India over the twentieth and twenty-first centuries, and a global diaspora now maintains temple priesthood, classical learning and ritual practice in North America, Europe and elsewhere far from any of the regional homelands the varna's internal communities trace themselves to.