From the 8th to13th century, Daman and Diu, which was a part of Goa was a stronghold of the Chowda Rajputs who were ousted by the Waghalas who in turn were expelled by Muslims in1330. It continued under Muslims rule for another two hundred years when it was conquered by the Portuguese. The Portuguese ruled Goa for 451 years (1510-1961). Albuquerque entrenched himself in the Island of Tiswadi in1510. His successors had unbroken sway over this lovely territory for four and a half centuries despite mounting resentment and opposition to the alien rule from the people within and outside the territory. Even as the Portuguese were settling down, admirals and seamen of the Indian powers were challenging their might on the high seas.

When Bahadur Shah, Sultan of Gujarat, was attacked by the Mughal Emperor Humayun he entered into a defensive alliance with the Portuguese and allowed them in 1535 to construct a fortress on the Island and maintain a garrison there. Later several attempts were made by the rulers of Gujarat in 1536, 1545 and 1546 respectively to oust the Portuguese from the Fort of Diu but to no avail. By the Treaty of 1543 the cessation of Diu to the Portuguese was finally confirmed. The fortress of Diu, an imposing structure was reconstructed after the siege of 1545 by Dom Joao de Castro.

By the middle of the 16th century the Portuguese were able to annex Salcete and Bardez Talukas and the coastal areas, north of Bombay and the pockets of Daman and Diu.

In 1670, a small armed band of the Arabs of Muscat surprised and plundered the fortress, retiring with the booty they had acquired. Since that happening, the other most worthy event occurred in connection with the liberation of Portuguese settlement-'Operation Vijay' just before the midnight of December 16, 1961, ending the colonial rule. The different land blocks on the west coast of India, Daman, Diu and Goa came to form one political unit after liberation from the erstwhile Portuguese regime in 1961. In 1987, when Goa become a full fledged state, Daman and Diu was separated from Goa.