The Stratigraphy of Pattanam: What Numismatics Reveals About Early Chera Port Networks

For centuries, historians seeking the ancient Malabar port of Muziris relied on textual descriptions from maritime guides like the Periplus Maris Erythraei (Navigation of the Erythraean Sea, a first-century CE Greek sailing manual) and Tamil Sangam poems (caṅka ilakkiyam, early South Asian classical literature). These records described foreign ships laden with gold anchoring along the coast to exchange bullion for black pepper, fine textiles, and beryl. Archaeological fieldwork led by the Kerala Council for Historical Research (KCHR) at Pattanam, near the mouth of the Periyar River, has shifted this discussion from literary interpretation to physical stratigraphy.

The site covers roughly 111 hectares in the Ernakulam district. Excavations at Pattanam have unearthed over 100,000 artifacts across distinct soil layers, establishing physical sequence data for early Indian Ocean commerce. The stratigraphic positions of Roman silver denarii (standard Roman silver coins) alongside native square copper coinage offer clear evidence for how local Chera (cēra, an early South Indian dynasty) authorities integrated foreign precious metals into regional trade networks.

+-------------------------------------------------------------------+
| Historical Era & Stratigraphic Layer | Material Assemblages       |
+-------------------------------------------------------------------+
| Medieval to Modern                   | Local utilitarian ceramics |
| (6th Century CE - Present)           | and structural disturbances|
+-------------------------------------------------------------------+
| Early Historic                       | Roman denarii, Chera coins,|
| (3rd Century BCE - 5th Century CE)   | amphorae, terracotta brick |
+-------------------------------------------------------------------+
| Iron Age / Megalithic                | Local pottery, iron tools, |
| (1000 BCE - 3rd Century BCE)         | glass and stone beads      |
+-------------------------------------------------------------------+

Layered Contexts and the Locus Methodology

To process complex, waterlogged soil deposits, field teams implemented locus methodology—a technique where every soil feature, cut, and structure is assigned an individual context number and linked sequentially through a Harris Matrix (a diagram showing the chronological sequence of archaeological layers). This approach prevents surface finds from contaminating sealed cultural layers.

Evidence shows that the lowest occupational strata at Pattanam date to the Iron Age (roughly 1000 BCE to 300 BCE). The transition into the Early Historic period (3rd century BCE to 5th century CE) is marked by brick structures, ring wells, a 6-meter wooden canoe carved from anjili (Artocarpus hirsutus, a wild jackfruit tree native to the Western Ghats), and teakwood mooring posts.

Directly associated with these maritime harbour contexts are thousands of imported pottery sherds, including Roman Mediterranean amphorae (two-handled storage jars used for wine and olive oil), Italian terra sigillata (fine red-gloss tableware), and West Asian torpedo jars.

Imperial Mints and Physical Coin Evidence

While large hoards of Roman aurei (gold coins) and denarii have historically been found buried in inland caches across Tamil Nadu and Kerala—such as the famous Vellalur hoard (RIC I Augustus 207) or the Coimbatore hoards—those surface finds lacked secure stratigraphic context. Excavations at Pattanam recovered coins directly within controlled archaeological trenches, linking specific Roman imperial minting periods to local occupation layers.

The numismatic record at Pattanam includes Roman silver issues alongside native Chera currency:

1. Augustan and Tiberian Denarii: Roman silver coins featuring the portraits of Augustus (ruled 27 BCE – 14 CE) and Tiberius (ruled 14 CE – 37 CE). The Tiberian denarius—frequently minted with the PONTIF MAXIM (Pontifex Maximus, high priest) reverse showing Livia seated (catalogued as RIC I Tiberius 26)—dominates early Roman silver imports along the Malabar coast.
2. Square Chera Copper Issues: Die-struck and cast copper coins carrying traditional Chera royal symbols, including the bow and arrow, elephant, and river emblems.
3. Punch-Marked Silver Coins: Early Indian silver currency originating in northern and central river valleys, circulating alongside overseas bullion.

The stratigraphy confirms that Roman silver arrived during the Julio-Claudian era (27 BCE – 68 CE). Rather than acting purely as legal tender within local markets, evidence shows these silver coins functioned as imported bullion or high-value currency converted into regional assets.

⚖ Scholarly Debate: The Muziris Identification

Scholars debate whether Pattanam is indeed the historical port of Muziris mentioned in Greco-Roman texts and Tamil Sangam literature.

One school of thought argues that Pattanam's extensive maritime artifacts—the canoe, mooring posts, amphorae, and Roman numismatic finds—provide definitive material proof that Pattanam was Muziris. Proponents point out that no other coastal site in Kerala has yielded a comparable density of Mediterranean trade goods dating to the 1st century BCE through 1st century CE.

Conversely, skeptics and rival historians contend that Pattanam lacks major civic or monumental stone architecture expected of a prime emporium described in classical literature. Some scholars propose alternative locations, such as Kodungallur further north along the Periyar delta, or suggest that "Muziris" represented a broader estuarine port complex rather than a single tightly bounded settlement.

[ Western Indian Ocean Trade Routes ]
               │
               ▼
   [ Pattanam Port Network ]  <─── (Periyar River Delta)
               │
               ├──────────────────────────────┐
               ▼                              ▼
  [ Kodumanal Production Sites ]   [ Karur Interior Capital ]
  (Beryl mining, Carnelian beads)   (Chera Royal Treasury)

Hinterland Supply Chains and Inland Distribution

The spatial distribution of coins demonstrates that Pattanam was not an isolated coastal enclave. It functioned as a key maritime node connecting transoceanic routes to inland manufacturing centers.

Inland sites such as Kodumanal (a gem-cutting and iron-smelting center in Tamil Nadu) and Karur (the inland Chera capital on the Amaravathi River) have produced identical assemblages of Roman silver coins, punch-marked coins, and Chera copper currency.

Scholars debate the exact mechanism of this interior trade. Some economic historians argue that foreign denarii were kept intact as prestige items and trade guarantees by local chieftains. Others suggest that imported silver was rapidly melted down by native artisans to produce local jewelry, pointing to the scarcity of late 2nd-century Roman silver in stratified coastal layers.

The Physical Archive of the Malabar Coast

The physical sequence at Pattanam grounds long-standing textual narratives in verifiable material evidence. By evaluating Roman silver denarii directly within their stratigraphic contexts, field archaeology has transformed the study of ancient South Asian trade. The presence of imperial Roman silver embedded alongside local Chera coinage demonstrates that early Malabar ports operated within a structured, highly organized global economy.

Sources

• Cherian, P.J. et al. (2014). Pattanam Excavations Reports (2007–2014). Kerala Council for Historical Research (KCHR). https://www.kchr.ac.in
• Casson, Lionel. (1989). The Periplus Maris Erythraei: Text with Introduction, Translation, and Commentary. Princeton University Press. https://press.princeton.edu/books/hardcover/9780691035864/the-periplus-maris-erythraei
• Gurukkal, Rajan. (2013). "Is Pattanam Muziris?" Economic and Political Weekly, 48(19). https://www.epw.in/journal/2013/19/special-articles/pattanam-muziris.html
• Mattingly, Harold. (1923). Coins of the Roman Empire in the British Museum (BMCRE), Vol. I: Augustus to Vitellius. British Museum Press. https://www.britishmuseum.org
• Tomber, Roberta. (2008). Indo-Roman Trade: From Ports to Pepper. Duckworth Archaeology Series. https://www.bloomsbury.com