The Samoothiri (Anglicised as Zamorin; Malayalam: ISO, saːmuːd̪iɾi, Arabic: Sāmuri, Portuguese: Samorim, Dutch: Samorijn, Chinese: Shamitihsi) was the hereditary Nair monarch and ruler of the Kingdom of Kozhikode (Calicut) in the South Malabar region of India. Originating from the former feudal kingdom of Nediyiruppu Swaroopam, the Samoothiri and his vassal kings from Nilambur Kovilakam established Calicut as one of the most important trading ports on the southwest coast of India. The 147th Samoothiri Raja, Sree Manavedan Raja, who was married to Bharathy Thamburatty from Nilambur Kovilakam, became the last Zamorin in the dynasty's 682 year history to hold power over the Guruvayur Temple. At the peak of their reign, his ancestors ruled over a region extending from Kozhikode Kollam (Kollam) to the forested borders of Panthalayini Kollam (Koyilandy). The Zamorins belonged to the Eradi caste of the Samantan Nair community of colonial Kerala.
It was after the dissolution of the kingdom of Cheras of Kodungallur in the early 12th century that the Samanthan Nair Eradis of Nediyiruppu (originally autonomous chiefs of Eranadu) demonstrated their political independence under the title of Zamorin. The Zamorins maintained elaborate trade relations with the Muslim Middle-Eastern sailors in the Indian Ocean, the primary spice traders on the Malabar Coast during the Middle Ages. Calicut was then an important entrepôt in South-Western India where Chinese and West Asian trade collaborated.
The port at Kozhikode held the superior economic and political position along the medieval Kerala coastline, while Kannur, Kollam, and Kochi, were commercially important secondary ports, where traders from various parts of the world would gather. The Portuguese navigator Vasco da Gama visited Quilandy in 1498, opening the sailing route directly from Europe to South Asia. The port at Kozhikode acted as the gateway to medieval South Indian coast for the Arabs, the Chinese, the Portuguese, the Dutch, and finally the British.