In Hindu caste structures, there are four major castes, each divided into sub-castes. The modern hierarchy of the castes places Brahmins (priests, teachers, temple officials) first, Kshatriyas (warriors, feudal lords, land-owners) second, Vayshas (traders in goods) third and Sudras (traders in services) fourth. At times in the past, Brahmin and Kshatriya castes alternated at the top of the structure. Vellalan is a sub-caste at the top of the Kshatriya caste.

In Sri Lanka, the highest caste below the King and the Royal family in the social order among ancient Tamils was the Vellalan caste, who were traditionally the warriors, land owners and rulers. During the reign of the usurper king Sangili II, the rightful heirs to the throne (the children of Prince Paranirupasingham), were offered alternative titles to compensate for no-longer being in line for the throne. Sangili wanted them to be called Mudaliyars (or Mudali - in Christopher Britto's translation of the Yalpana Vaipava Malai). Confusingly, this is also a caste name akin to the Vellalans in India. Paranirupasingham and his son Pararasasingham declined to accept this title, but Pararasasingham's children did appear to accept it. In order to distinguish themselves from other Mudaliyars in Sri Lanka, they also referred to themselves as 'Madapali', which, according to some sources, was the ancestral home of original Ariya Chakravarti king, Vijeya Kulangkai Kalinga Magan (Kalinga Magan means 'son/child of Kalinga', which was the kingdom where the royal village of Madapali could be found). This construction is at odds with some of the historical documents, because according to some documents, Vijeya Kulangkai came from Rameswaram in the very far south of Tamil Nadu (see de Queroz' book on Ceylon) It is possible that he descended from Kalinga kings but lived in Rameswaram, and even though his ancestors came from Kalinga, he was more correctly associated with the Pandyans and Rameswaram than he was with Kalinga because of generations of living there. Similarly, there are confusing accounts on why Ariyar is in the title of the Chakravarti kings - some say it is a result of their connection with the city of Rameswaram, which is a holy city believed in legend to have been established by the god Rama (documented in the Ramayana). The word (meaning 'noble' or 'pure') is associated with the Brahmin caste. There is some confusion on this point between the main sources (Mudaliyar Rasanayagam's Ancient Jaffna and Christopher Britto's translation of the Yalpana Vaipava Malai are the two main ones). According to one theory, the Ariyar Chakravartis were Brahmins rather than Vellalan. It is more likely that they were Vellalans from Kalinga given high office under the Pandyan Kings and married Brahmin princesses from Rameswaram.

Chetty, or Chettiar, is a sub-caste of the Vaysha caste, traditionally associated with trade in goods (as distinct from Sudras, who traded in services). The Chetties of Ceylon originated in Tamil Nadu and Kerala and traded along the Malabar and Coromandel coasts with the coastal ports of Sri Lanka. By the time of the Portuguese arrival in Sri Lanka, these communities had established small outposts along the North Eastern and North Western coasts of Sri Lanka. At some point, a famine in India caused many Chetties to relocate to join their relatives in Sri Lanka. Coming under Portuguese influence, these communities converted to Catholicism. Due to their great collective wealth, many moved to Colombo and established trading houses there. The Portuguese, Dutch and later British appointed many Chetties to high office, as they were considered reliable (due partly to their religious affiliations and partly to their access to excellent education in the colonial urban centres). Thus some Chetty families became extremely influential. As they had close association with the Tamils, both in Jaffna and in Colombo, many Chetties married Christian Tamil families. As many of the Madapali had converted to Catholicism during the Portuguese rule, these communities mingled.