Earliest curry in Southeast Asia and the global spice trade 2000 years ago

The site of Oc Eo

Oc Eo is located on the border between An Giang and Kien Giang provinces on the southwestern side of the Mekong Delta, southern Vietnam. It now lies about 25 km from the sea, within a network of ancient canals (Supplementary Materials, fig. S1). The whole site complex covers an area of some 2,500 ha, including the lower slopes and summit of Mount Ba The and an adjacent floodplain to its southeast that has several natural but low-lying mounds (Fig. 2; Supplementary Materials, Supplementary Text and fig. S2).

After the first excavation campaign conducted by French archaeologist Louis Malleret in the 1940s, Oc Eo was recognized as a major overseas trading center of the ancient Funan kingdom. The site also contained Hindu and Buddhist religious monuments and was a center for the processing of metals, glass for jewelry, and pottery (14). The 14C (Carbon-14) dates from Oc Eo reveal a major occupation between the first and eighth centuries CE, with the fourth to sixth centuries CE thought to have witnessed the greatest prosperity, when a series of canals, religious monuments, and residential settlements were created (14) (Fig. 3; Supplementary Materials, Supplementary Text, figs. S3 to S5, and table S1). A few pieces of Islamic pottery dating from the eighth century represented the final habitation, when the site was abandoned perhaps because of a marine incursion (14).

The data analyzed

This study focuses on microscopic plant remains extracted from 12 food preparation tools found at Oc Eo, illustrated in Fig. 4 and listed in Supplementary Materials, table S2. In South Asia, ground stone processing implements of the types found at Oc Eo are reported from many archaeological sites that date especially to the early historical period (ca. 500 BCE to 300 CE) (17). Similar stone tools have remained widely in use in India until recent centuries (Fig. 5).

At Oc Eo itself, one 14C date of 207 to 326 cal. CE (14C laboratory code: PLD-45555) came from a charcoal sample collected from slightly below our largest grinding slab (sample code OE18.LLO.B.H1.M1.L3.3) (Fig. 6) (Supplementary Materials, fig. S6 and table S1). This date falls well within the occupation span at Oc Eo (14, 24). Presumably, tools of these South Asian types were initially brought to Oc Eo by migrants and later manufactured locally (16). More generally, small-scale population movement from South into Southeast Asia is attested as early as the first to third centuries CE by ancient DNA from the Vat Komnou cemetery at Angkor Borei (25).

Turmeric (C. longa)

Turmeric most probably originated in South Asia, where the greatest diversity of Curcuma species and the earliest turmeric remains occur (32) (Fig. 9). Starch grains from turmeric have been extracted from Harappan (2600 to 2200 BCE) cooking pots and human teeth found at Farmana in Haryana (33). Turmeric was involved in trading systems between South Asia and the Mediterranean by the middle of the second millennium BCE, indicated by the turmeric protein identified in the dental calculus of an individual from Bronze Age Megiddo in Israel (3). Furthermore, turmeric is mentioned in Assyrian medical texts from Ashurbanipal’s library at Nineveh (seventh century BCE; 3, 34). In Southeast Asia, turmeric was perhaps introduced to produce yellow dye for the robes of Buddhist monks (35, 36). Archaeobotanical findings of turmeric were unknown in Southeast Asia before this study, and the large quantity of turmeric starch found at Oc Eo underlines the culinary influence there of Indian culture.

Ginger (Z. officinale)

Ginger originated in the Indo-Malaysian region, but the primary domestication center remains obscure (37). China and India have been suggested as two major cultivation centers and suppliers of ginger for trade since ancient times (38) (Fig. 9). China has the oldest written record for its presence, from the Analects of Confucius written in the Warring States period (475 to 221 BCE) (39). However, ginger starch has been recovered from the Harappan site of Farmana in India (33). In China, more than 78 pieces of ginger have been found from seven ancient burials from the late Warring States period to early Western Han Dynasty (300 to 160 BCE) (40) (Supplementary Materials, table S5). Ginger was well known to the West in the first century CE, and references to its medicinal and spice usages occur in Persian, Arabic, Greek, and Roman texts (6, 34).

Other ginger plants

The other edible Zingiberaceae species found at Oc Eo—galangal (A. galanga), fingerroot (B. rotunda), and sand ginger (K. galanga)—are all native to tropical Asia and widely cultivated today in Southeast Asia. Their precise origins are uncertain (41, 42), but it is possible that galangal originated in Java (38), fingerroot in Sumatra and Java (2, 43), and sand ginger less precisely in either South or Southeast Asia (44) (Fig. 9). So far, traces of these ginger species have been absent in archaeological records, except for a seed of Alpinia sp. identified from the temple of Ta Prohm at Angkor, with a radiocarbon date that falls within ca. 8th through 10th centuries CE (23).

Thus far, no other finds of galangal have been reported from the archaeological record, but seeds of the related shell ginger (Alpinia cf. zerumbet) have been recovered from Kantharodai (ca. 200 BCE) and Kirinda (ca. 260 to 900 CE) in Sri Lanka (45). Lesser galangal (Alpinia officinarum) is reported from the Mawangdui Western Han Tomb (second century BCE) in Hunan province, China (46). The Roman author Apicius used galangal in his recipes, and galangal figured in early trade from Asia to Europe (47). Medicinal uses of galangal are recorded in Sanskrit texts that date back to 600 CE (6). The other two Zingiberaceae species—fingerroot (B. rotunda) and sand ginger (K. galanga)—are used today as seasonings and herbal medicines and also have a long history of utilization in Southeast Asia (48, 49).

Clove (S. aromaticum)

Clove trees are native to the volcanic islands of Maluku Utara (northern Moluccas), often termed the “Spice Islands” (50) (Fig. 9). The common term “clove” refers to the clove bud, but the clove seed, termed “chicken-tongue spice” in Chinese texts, was also a traditional spice and medicine. Several historical documents suggest that cloves reached China, India, and Rome during the late centuries BCE to early CE. For instance, according to the Han Guan Yi (Etiquettes of the Officialdom of the Han Dynasty) completed ca. 200 CE, the Han Dynasty court had a rule that ministers should suck cloves to sweeten their breath before speaking to the emperor (51). Cloves are mentioned in the Ramayana, an Indian epic written between 350 BCE and 1 CE, and are reputed according to Pliny’s Natural History (70 CE) to have been known in Rome (22, 52).

Before this study, the earliest potential evidence for cloves, dated to ca. 1700 BCE, came from the Middle Bronze Age site of Terqa in Syria, but the identification remains controversial (53, 54). A carbonized clove was excavated from the deposit of ca. 900 to 1100 CE in the ancient port of Mantai in Sri Lanka, South Asia (21). In West Java, a clove was recovered from the lower waterlogged layer (second century BCE to third century CE) at the Segaran IIA site at Batujaya (55). Notably, a few ceramic shards from Batujaya resemble pottery at Oc Eo and suggest contact (55). It is unclear whether cloves were directly obtained from source plantations in the Moluccas or whether the tree was planted in islands to the west of the Moluccas (such as Java) from an early date. Clove plantations occur in many Indonesian islands today.

Nutmeg (M. fragrans)

The earliest direct evidence of nutmeg comes from the Banda islands, where it originated (50, 56) (Fig. 9). Potsherds excavated from Neolithic layers (ca. 1500 to 300 BCE) in Pulau Ay site 1 have produced starch grains from nutmeg (56). Far to the west, claims for nutmegs at Deir el-Bahari (16th to 14th centuries BCE) in Egypt and at Yavneh (ca. 9th century BCE) in Israel remain unsubstantiated by definite identification (57, 58). More convincingly, carbonized nutmeg from Khairadih in eastern Uttar Pradesh (Ganges Valley) has been dated to an early phase of the Northern Black Polished Ware Culture (700 to 200 BCE) (22), and to the Kushan period from a fire altar at Sanghol (100 to 300 CE) in Punjab (22) (Fig. 9). A document termed the Charaka Samhita, an Ayurvedic compendium dating from the first century CE with a particular focus on general and internal medicine, mentions nutmeg, mace (the seed covering of nutmeg) and cloves (22).

Nutmeg seeds were recovered during the recent excavations at Oc Eo. One is directly dated to 120 to 248 cal. CE (94.3% probability), and this is so far the oldest nutmeg specimen in Mainland Southeast Asia.

Cinnamon (Cinnamomum sp.)

Cinnamon is one of the most ancient spices in history. It can be obtained from several tree species in the genus Cinnamomum (59). “True cinnamon” usually refers to Ceylon cinnamon (Cinnamomum verum) and is native to Sri Lanka (60) (Fig. 9). Other cinnamons, more precisely called cassia, come from four species; Chinese cinnamon (Cinnamomum cassia), Saigon cinnamon (Cinnamomum loureiroi), Indonesian cassia (Cinnamomum burmannii), and Indian cassia (Cinnamomum tamala) (61, 62).

Cinnamon has been involved in global trade at least since 2000 years ago. Egyptian records suggest its use for embalming mummies (63) in the second millennium BCE, but the details are questionable because of lack of direct identification (58). Cinnamon has been reported from three sites in Israel dated between the 11th and late 10th centuries BCE (57), and a damaged flower dated to the 7th century BCE found at Heraion on the Greek island of Samos was probably C. cassia (64). Cinnamon is also mentioned in the Old Testament and Pliny’s Natural History (65, 66, 67).

The microremains from Oc Eo show similar morphologies to Ceylon cinnamon from Sri Lanka. The discovery of cinnamon residues on the Oc Eo tools indicates its long-term utilization in Southeast Asia.

Other nonspice plants

Apart from spices, carbonized rice grains are common at Oc Eo, as also at Angkor Borei, where rice husks occur in earthenware pottery and bricks (68). The starch grains and phytoliths of rice from Oc Eo support the existence of a well-developed agricultural system as the basis for the Funan economy, echoing historical records (69). The canal systems recorded by Malleret in ancient Oc Eo (Supplementary Materials, fig. S1) would have provided irrigation water, just as such canals do today (69).

Palm products were also economically important in ancient Southeast Asia, for building houses, providing fibers for rope, and boat construction and in cooking and for alcoholic beverages (21). The legend of Funan in the Chinese Book of Liang (sixth century CE) records procedures for making palm wine in Southeast Asia, including the cutting of flowers, collection of sap, and fermentation in pots to make the wine.

This study of microremains on stone grinding and pounding tools from Oc Eo has revealed that Funan people used spices from several species indigenous to South and Southeast Asia, including turmeric, ginger, galangal, sand ginger, fingerroot, clove, nutmeg, and cinnamon. Species in the family Zingiberaceae were especially prominent. All of these spices can be used as ingredients for making curry (Fig. 5), and some, such as cinnamon, nutmeg, and clove, might have been imported to Oc Eo from distant locations in South Asia and eastern Indonesia (Fig. 9). However, the possibility that these species were reproduced from seed stock in places far from their homelands, at dates close to their entry into culinary repertoires, needs always to be borne in mind.

Perhaps the history of curry began more than 4000 years ago in Harappan Pakistan and India, where starch grains of turmeric, ginger, eggplant, and mango have been found attached to human teeth and in cooking pots (33). Today, curry is still popular in Southeast Asia (70), and the ingredients recovered from Oc Eo are matched more closely in modern Southeast Asia than in South Asia in being mixed with endemic spices and thickened by coconut milk. For example, galangal is a common component of curry pastes in Southeast Asia but is seldom used in Indian curry (18), likewise fingerroot and sand ginger in Thai curry (71).

Considering multiple lines of evidence, particularly the newly found spices from this study and their association with Indian-style preparation tools, we may conclude that curry recipes arrived in Southeast Asia with South Asian traders and migrants as contacts intensified during the early centuries CE. This study thus bolsters our knowledge about how South Asian cultures influenced the formation of early Southeast Asian cuisines, especially in light of the dynamic role of ancient Oc Eo, in southern Vietnam, within global maritime trade networks.

The global spice trade has linked cultures and economic systems in Asia, Africa, and Europe since Classical times. Our findings provide direct evidence for a role in this trade of the ancient port city of Oc Eo, by at least 2000 to 1800 years ago. Oc Eo likewise maintained contacts westward with the Indian subcontinent and, more distantly, the Mediterranean world. Our findings also highlight the importance of the Moluccas as the ultimate source region for cloves and nutmegs.

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