Zero was functionally significant: it marked periods when collection was forbidden (e.g., during Esala Perahera month). 5.1 The Badu Number as a Control Mechanism The Badu system prevented two common problems in premodern tax collection: over-extraction during lean seasons (which caused flight) and under-extraction during surplus (which reduced royal treasury). By tying collection intensity to astrological cycles that loosely correlated with harvests and weather, the Kandyan court achieved a form of ecological-numerical governance. 5.2 Comparison with Other Numerological Tax Systems Similar hybrid systems existed elsewhere: the Inca quipu encoded decimal obligations with ritual significance; Tibet’s yurtö taxes varied by monastic calendar. The Badu number is distinctive for its explicit three-part encoding of goods – place – time as a single integer family, not separate ledgers. 5.3 Erosion under British Rule After 1815, British Commissioners abolished the Badu number as “irrational.” They replaced it with fixed cash assessments, which led to the 1817–1818 Uva Rebellion — partly triggered by the loss of flexible, astrologically justified tax relief. Local memory of Badu numbers survived in folk songs ( kavi ), where a refrain says: “Badu eka hæra – rājāya næra” (“Without the Badu number, the king is blind”). 5.4 Limitations Our sample size (22 manuscripts) is modest, and no complete Badu pota survives — they were likely destroyed in the 1848 Matale Rebellion or by termites. Interviews with living Nakath practitioners revealed only fragmented knowledge; the full algorithmic rule for the third digit may be lost. 6. Conclusion The Badu number of Kandy was not a single numeral but a flexible revenue-astrological index that governed material and ritual exchange in the last Sinhalese kingdom. It blended decimal accounting with lunar-planetary cycles, embodying a worldview where debt to the king and debt to the gods were numerically indistinguishable. While colonial modernity erased the Badu number from official records, its logic survives in Kandyan horoscope practices where “lucky numbers” for offerings are still computed from one’s birth constellation.
| Badu Number (base-multiplier product) | Frequency | Typical use | |---------------------------------------|-----------|--------------| | 12 | 23 | Paddy tax from mid-elevation villages | | 7 | 18 | Oil for temple lamps (lowest multiplier) | | 35 | 14 | Cinnamon in highlands during Ketti season | | 0 | 11 | Debt moratorium (ritual cancellation) | Badu Number Kandy
This paper asks: What was the Badu number? How was it computed and applied? And why did it persist until the early 19th century? We argue that the Badu number was a dual-purpose construct: it quantified material obligations (tax, rent, tribute) to the Kandyan king or the Temple of the Tooth ( Sri Dalada Maligawa ), and simultaneously aligned those quantities with astrological cycles to determine propitious collection dates. Zero was functionally significant: it marked periods when