A substantial portion of Kerala may have been under the sea in ancient times. Marine fossils have been found in an area near Changanacherry, thus supporting the hypothesis. Pre-historical archaeological findings include dolmens of the Neolithic era in the Marayur area of the Idukki district. They are locally known as “muniyara”, derived from muni (hermit or sage) and ara (dolmen). Rock engravings in the Edakkal Caves, in Wayanad date back to the Neolithic era around 6000 BCE. Archaeological studies have identified Mesolithic, Neolithic and Megalithic sites in Kerala. The studies point to the development of ancient Kerala society and its culture beginning from the Paleolithic Age, through the Mesolithic, Neolithic and Megalithic Ages. Foreign cultural contacts have assisted this cultural formation, historians suggest a possible relationship with Indus Valley Civilization during the late Bronze Age and early Iron Age.
Kerala has been a major spice exporter since 3000 BCE, according to Sumerian records and it is still referred to as the “Garden of Spices” or as the “Spice Garden of India”. Kerala’s spices attracted ancient Babylonians, Assyrians and Egyptians to the Malabar Coast in the 3rd and 2nd millennia BCE. Phoenicians established trade with Kerala during this period. The Land of Keralaputra was one of the four independent kingdoms in southern India during Ashoka’s time, the others being Chola, Pandya, and Satiyaputra. Scholars hold that Keralaputra is an alternate name of the Cheras, the first dominant dynasty based in Kerala. These territories once shared a common language and culture, within an area known as Tamilakam. Along with the Ay kingdom in the south and the Ezhimala kingdom in the north, the Cheras formed the ruling kingdoms of Kerala in the early years of the Common Era (CE). It is noted in Sangam literature that the Chera king Uthiyan Cheralathan ruled most of modern Kerala from his capital in Kuttanad, and controlled the port of Muziris, but its southern tip was in the kingdom of Pandyas, which had a trading port sometimes identified in ancient Western sources as Nelcynda (or Neacyndi) in Quilon. The lesser known Ays and Mushikas kingdoms lay to the south and north of the Chera regions respectively.
Silk Road map. The spice trade was mainly along the water routes (blue).
In the last centuries BCE the coast became important to the Greeks and Romans for its spices, especially black pepper. The Cheras had trading links with China, West Asia, Egypt, Greece, and the Roman Empire. In foreign-trade circles the region was known as Male or Malabar. Muziris, Berkarai, and Nelcynda were among the principal ports at that time. The value of Rome’s annual trade with the region was estimated at around 50,000,000 sesterces, contemporary Sangam literature describes Roman ships coming to Muziris in Kerala, laden with gold to exchange for pepper. One of the earliest western traders to use the monsoon winds to reach Kerala was Eudoxus of Cyzicus, around 118 or 166 BCE, under the patronage of Ptolemy VIII, king of the Hellenistic Ptolemaic dynasty in Egypt. Roman establishments in the port cities of the region, such as a temple of Augustus and barracks for garrisoned Roman soldiers, are marked in the Tabula Peutingeriana; the only surviving map of the Roman cursus publicus.
Merchants from West Asia and Southern Europe established coastal posts and settlements in Kerala. The Israeli (Jewish) connection with Kerala started in 573 BCE. Arabs also had trade links with Kerala, starting before the 4th century BCE, as Herodotus (484–413 BCE) noted that goods brought by Arabs from Kerala were sold to the Israelis [Hebrew (Jews)] at Eden. Israelis intermarried with local (Cheras Dravidian) people, resulting in formation of the Mappila community. In the 4th century, some Christians also migrated from Persia and joined the early Syrian Christian community who trace their origins to the evangelistic activity of Thomas the Apostle in the 1st century. Mappila (Semitic) was an honorific title that had been assigned to respected visitors from abroad; Israelite(Jewish), Syrian (Aramaic) Christian, and Muslim immigration account for later names of the respective communities: Juda Mappilas, Nasrani Mappilas, and Muslim Mappilas. The earliest Saint Thomas Christian Churches, Cheraman Juma Masjid (629 CE)—the first mosque of India—and Paradesi Synagogue (1568 CE)—the oldest active synagogue in the Commonwealth of Nations—were built in Kerala.
Early medieval period
Tharisapalli plates granted to Saint Thomas Christians testify that merchant guilds and trade corporations played a very significant role in the economy and social life during the Kulasekhara period.
A second Chera Kingdom (c. 800–1102), also known as Kulasekhara dynasty of Mahodayapuram (present-day Kodungallur), was established by Kulasekhara Varman, which ruled over a territory comprising the whole of modern Kerala and a smaller part of modern Tamil Nadu. During the early part of the Kulasekara period, the southern region from Nagerkovil to Thiruvalla was ruled by Ay kings, who lost their power in the 10th century, making the region a part of the Kulasekara empire. Under Kulasekhara rule, Kerala witnessed a developing period of art, literature, trade and the Bhakti movement of Hinduism. A Keralite identity, distinct from the Tamils, became linguistically separate during this period around the seventh century. For local administration, the empire was divided into provinces under the rule of Naduvazhis, with each province comprising a number of Desams under the control of chieftains, called as Desavazhis.
The inhibitions, caused by a series of Chera-Chola wars in the 11th century, resulted in the decline of foreign trade in Kerala ports. In addition, Portuguese invasions in the 15th century caused two major religion Buddhism and Jainism to disappear from the land. It is known that the Menons in the Malabar region of Kerala were originally strong believers of Jainism. The social system became fractured with divisions on caste lines. Finally, the Kulasekhara dynasty was subjugated in 1102 by the combined attack of Later Pandyas and Later Cholas. However, in the 14th century, Ravi Varma Kulashekhara (1299–1314) of the southern Venad kingdom was able to establish a short-lived supremacy over southern India. After his death, in the absence of a strong central power, the state was divided into thirty small warring principalities; the most powerful of them were the kingdom of Samuthiri in the north, Venad in the south and Kochi in the middle. In the 18th Century, Travancore King Sree Anizham Thirunal Marthanda Varma annexed all the kingdoms up to Northern Kerala through military conquests, resulting in the rise of Travancore to pre-eminence in Kerala. The Kochi ruler sued for peace with Anizham Thirunal and Malabar came under direct British rule until India became independent.
The state is wedged between the Lakshadweep Sea and the Western Ghats. Lying between northern latitudes 8°18′ and 12°48′ and eastern longitudes 74°52′ and 77°22′, Kerala experiences the humid equatorial tropic climate. The state has a coast of 590 km (370 mi) and the width of the state varies between 11 and 121 kilometres (7 and 75 mi). Geographically, Kerala can be divided into three climatically distinct regions: the eastern highlands; rugged and cool mountainous terrain, the central mid-lands; rolling hills, and the western lowlands; coastal plains. Pre-Cambrian and Pleistocene geological formations compose the bulk of Kerala’s terrain. A catastrophic flood in Kerala in 1341 CE drastically modified its terrain and consequently affected its history; it also created a natural harbour for spice transport. The eastern region of Kerala consists of high mountains, gorges and deep-cut valleys immediately west of the Western Ghats’ rain shadow. 41 of Kerala’s west-flowing rivers, and 3 of its east-flowing ones originate in this region.The Western Ghats form a wall of mountains interrupted only near Palakkad; hence also known Palghat, where the Palakkad Gap breaks. The Western Ghats rise on average to 1,500 metres (4,900 feet) above sea level, while the highest peaks reach around 2,500 metres (8,200 feet). Anamudi in the Idukki district is the highest peak in south India, is at an elevation of 2,695 m (8,842 ft).
Kerala’s western coastal belt is relatively flat compared to the eastern region, and is criss-crossed by a network of interconnected brackish canals, lakes, estuaries, and rivers known as the Kerala Backwaters. The state’s largest lake Vembanad, dominates the backwaters; it lies between Alappuzha and Kochi and is about 200 km2 (77 sq mi) in area. Around eight percent of India’s waterways are found in Kerala. Kerala’s 44 rivers include the Periyar; 244 kilometres (152 mi), Bharathapuzha; 209 kilometres (130 mi), Pamba; 176 kilometres (109 mi), Chaliyar; 169 kilometres (105 mi), Kadalundipuzha; 130 kilometres (81 mi), Chalakudipuzha; 130 kilometres (81 mi), Valapattanam; 129 kilometres (80 mi) and the Achankovil River; 128 kilometres (80 mi). The average length of the rivers is 64 kilometres (40 mi). Many of the rivers are small and entirely fed by monsoon rain. As Kerala’s rivers are small and lacking in delta, they are more prone to environmental effects. The rivers face problems such as sand mining and pollution. The state experiences several natural hazards like landslides, floods and droughts. The state was also affected by the 2004 Indian Ocean tsunami.
With around 120–140 rainy days per year80 Kerala has a wet and maritime tropical climate influenced by the seasonal heavy rains of the southwest summer monsoon and northeast winter monsoon. Around 65% of the rainfall occurs from June to August corresponding to the Southwest monsoon, and the rest from September to December corresponding to Northeast monsoon. The moisture-laden winds of the Southwest monsoon, on reaching the southernmost point of the Indian Peninsula, because of its topography, divides into two branches; the “Arabian Sea Branch” and the “Bay of Bengal Branch”. The “Arabian Sea Branch” of the Southwest monsoon first hits the Western Ghats, making Kerala the first state in India to receive rain from the Southwest monsoon. The distribution of pressure patterns is reversed in the Northeast monsoon, during this season the cold winds from North India pick up moisture from the Bay of Bengal and precipitate it on the east coast of peninsular India. In Kerala, the influence of the Northeast monsoon is seen in southern districts only. Kerala’s rainfall averages 2,923 mm (115 in) annually. Some of Kerala’s drier lowland regions average only 1,250 mm (49 in); the mountains of the eastern Idukki district receive more than 5,000 mm (197 in) of orographic precipitation: the highest in the state. In eastern Kerala, a drier tropical wet and dry climate prevails. During the summer, the state is prone to gale-force winds, storm surges, cyclone-related torrential downpours, occasional droughts, and rises in sea level.:26, 46, 52 The mean daily temperature ranges from 19.8 °C to 36.7 °C. Mean annual temperatures range from 25.0–27.5 °C in the coastal lowlands to 20.0–22.5 °C in the eastern highlands.:65