Odisha (; formerly rendered Orissa ) is one of the 29 states of India, located in the east of India. It is surrounded by the states of West Bengal to the north-east, Jharkhand to the north, Chhattisgarh to the west and north-west, Telangana to the south-west and Andhra Pradesh to the south. Odisha has 485 km of coastline along the Bay of Bengal on its east, from Balasore to Ganjam. It is the 9th largest state by area, and the 11th largest by population. Oriya (officially spelled Odia) is the official and most widely spoken language, spoken by 33.2 million according to the 2001 Census.
The ancient kingdom of Kalinga, which was invaded by the Mauryan emperor Ashoka in 261 BCE resulting in the bloody Kalinga War, coincides with the modern day Odisha. The modern state of Orissa was established on 1 April 1936, as a province in British India and consisted predominantly of Oriya speaking regions. Therefore, 1 April is celebrated as Utkala Dibasa (foundation day of Odisha). The region is also known as Utkala and is mentioned in India's national anthem, "Jana Gana Mana". Cuttack was made the capital of the region by Anantavarman Codaganga in c. 1135, after which the city was used as the capital by many rulers, through the British era until 1948 when Bhubaneswar replaced it as the capital.
Prehistoric Acheulian tools dating to Lower Paleolithic era have been discovered in various places in the region implying an early settlement by humans. Kalinga has been mentioned in ancient texts like Mahabharata, Vayu Purana and Mahagovinda Suttanta. The Sabar people of Odisha have also been been mentioned in the Mahabharata. Baudhayana mentions Kalinga as not yet being influenced by Vedic traditions, implying it followed mostly tribal traditions. However over time, the tribal people have adopted Hindu customs and traditions, the Bonda Paraja is one such tribe.
Ashoka of the Mauryan dynasty conquered Kalinga in the bloody Kalinga War in 261 BCE which was the 8th year of his reign. According to his own edicts, the war about 1,000,000 people were killed, 1,500,000 were captured and several more were affected. The resulting bloodshed and suffering of the war deeply affected Ashoka. He turned into a pacifist and converted to Buddhism.
By c.150 CE, emperor Kharavela, who was possibly a contemporary of Demetrius I of Bactria, conquered a major part of the Indian sub-continent. Kharavela was a Jain ruler. He also built the monastery atop the Udayagiri hill. Subsequently, the region was ruled under monarchs, such as Samudragupta and Shashanka. It was also a part of Harsha's empire.
Later, the kings of the Somavamsi dynasty, began to unite the region. By the reign of Yayati II, c.1025 CE, they had integrated the region into a single kingdom. Yayati II is supposed to have built the Lingaraj temple at Bhubaneswar. They were replaced by the Eastern Ganga dynasty. Anantavarman Codaganga who began construction on the present-day Jagannath Temple in Puri (c.1135) and Narasimhadeva I who constructed the Konark temple (c.1250).
The region had resisted integration into the Mughal empire until 1568, when it was conquered by Sultanate of Bengal. Mukunda Deva, who is considered the last independent king of Kalinga, was defeated and was killed in battle by Ramachandra Bhanja, a rebel chieftain. Ramachandra Bhanja himself was killed by Bayazid Khan Karrani. In 1591, Man Singh I, then governor of Bihar led an army to take Odisha from the Karranis of Bengal. They agreed to treaty because their leader Qutlu Khan Lohani had recently died. But, they broke the treaty by attacking temple town of Puri. Man Singh returned in 1592 and pacified the region. In 1751, the Nawab of Bengal Alivardi Khan ceded the region to the Maratha Empire.
The British had occupied the Northern Circars comprising the southern coast of Odisha as a result of the 2nd Carnatic War by 1760 and incorporated them into the Madras Presidency gradually. In 1803, the British under the ousted the Marathas from the Puri-Cuttack region of Odisha during the Second Anglo-Maratha War. The northern and western districts of Odisha were incorporated into Bengal Presidency.
The Orissa famine of 1866 caused an estimated death of 1 million. Following which, large-scale irrigation projects were undertaken. In 1903, the Utkal Sammilani organisation was founded to demand for the unification of Oriya speaking regions into one state. On 1 April 1912, the Bihar and Orissa Province was formed. On 1 April 1936, Bihar and Orissa were split into separate provinces. The new province of Orissa came into existence on linguistic basis during the British rule in India with Sir John Austen Hubback as the first governor. Following India's independence, on 15 December 1947, 27 princely states signed the document to join Orissa.