From the 2nd century BC to the 13th Century AD it formed part of the country known as Lata which was one of seven divisions of the Aparant of Konkan Vishaya. The edict of Emperor Ahoka (272-236 BC) are found at Girnar in Saurashtra and at Sopara near Bombay. The Daman District is included in the intervening region and must have formed part of Mauryan empire at least at the time of Ashoka and his religious order must have been followed by the people of Lata Country including Daman. Lata country was ruled by several kings during these period by Mauryans, Sungas, Satavahanas, Kshtrapas, abhiras till 416 AD. Then this district seems to have come under Chalukyas of Badami, Kalyani and Anhilwad in 1223 AD the southern part of Lata mandal including Daman seems to have been annexed to Yadava empire of Devagiri. By the middle of 13th Century Raipur prince ramashah during the Muslim conquest of Rajasthan came down to seak his fortune in the South and defeated Koli chief Nathorat of thorat tribe and established himself in the hilly track at Asheri near Daman about 1263 AD when allaudin Khilji, Emperor of Delhi, conquered the Gujarat from Chalukyas of Anhilwad, Deccan from Yadavas of Devagiri the capital was shifted to Nagar Fatapur from Nagar HAveli by Dharmshah successor of Ramashah. The border extended to river Auranga near Bulsar to the north of Daman. The ancient made route joined Nasik with port Daman via Peint and Surgana.
The Potuguese who landed at Clicut in 1498 AD and established at Goa in 1510 AD were carrying on depredation in the coastal areas during early part of the 16th century.
Two decade later the Portuguese began to regard the acquisition of Daman necessary for the security of their province of Bassein. The Governor of Goa sent a envoy to Shah was found willing to cede the place in return for one-half of the custom receipt of Diu. However, there was no possibility of acquiring Daman without force. The captain of Daman was on Abyssinian Chief with 3000 soldiers. He would not obey the orders from the royal court in Ahmedabad.
Early in 1559, the Governor of Goa, Constantino de Braganza sailed against Daman with fleet of more then 100 vessels with two or three thousand soldiers. The defence was well prepared. Several bulwarks were errected and provision for three or four months were stocked. Defenders planned to hold the place against the Portuguese until May when the monsoon would compel the latter to retreat. However, nothing stopped the Portuguese. They landed at Daman with virtually no resistance. The town was taken easily. The fortress too fell into their hands. No Portuguese life was lost in this.
Governor stayed in Daman for sometime, ordered the errection of new fort and left for Goa, leaving behind 1200 men with Diogo de Noronha as Captain-Major of Daman.
District of Daman and Diu became Union Territory after delinking from Goa which attained on the same day, 30th May 1987.