Bom Bahia in the context of Navi Mumbai

The State of India, also known as the Portuguese State of India or Portuguese India, was a state of the Portuguese Empire founded seven years after the discovery of the sea route to the Indian subcontinent by Vasco da Gama, a subject of the Kingdom of Portugal. The capital of Portuguese India served as the governing centre of a string of military forts and maritime ports scattered along the coasts of the Indian Ocean.

Francisco de Almeida, the first viceroy, established his base of operations at Fort Manuel in the Malabar region, after the Kingdom of Cochin negotiated to become a protectorate of Portugal in 1505. With the Portuguese conquest of Goa from the Bijapur Sultanate in 1510, Goa became the major anchorage for the Armadas arriving in India. The capital of the viceroyalty was transferred from Cochin to Goa in 1530. From 1535, Mumbai (Bombay) was a harbour of Portuguese India, known as Bom Bahia, until it was handed over to Charles II of England in 1661 as part of the dowry of Catherine de Braganza. The expression "State of India" began regularly appearing in documents in the mid-16th century.

The Portuguese conquered Goa when the governor Afonso de Albuquerque captured the city in 1510 from the Sultanate of Bijapur. Old Goa became the capital of Portuguese India, which included territories such as Fort Manuel of Cochin, Bom Bahia, Damaon, and Chaul. It was not among the places Albuquerque was supposed to conquer. He did so after he was offered the support and guidance of Timoji and his troops.

Albuquerque had been given orders by Manuel I of Portugal to capture Ormus, Aden, and Malacca only. Goa would remain under Portuguese control until 1961.

The Portuguese Indian Armadas (Portuguese: Armadas da Índia; meaning "Armadas of India") were the fleets of ships funded by the Crown of Portugal, and dispatched on an annual basis from Portugal to India. The principal destination was Goa, and previously Cochin. These armadas undertook the Carreira da Índia ('India Run') from Portugal, following the maritime discovery of the Cape route, to the Indian subcontinent by Vasco da Gama in 1497–99.

The annual Portuguese India armada was the main carrier of the spice trade between Europe and Asia during the 16th Century. The Portuguese monopoly on the Cape route was maintained for a century, until it was breached by Dutch and English competition in the early 1600s. The Portuguese India armadas declined in importance thereafter. During the Dutch occupation of Cochin and the Dutch siege of Goa, the harbour of Bom Bahia, now known as Mumbai (Bombay), off the coast of the northern Konkan region, served as the standard diversion for the armadas.

Old Goa (Konkani: Pornnem Gõy; Adlem Gõy; Portuguese: Velha Goa, lit. ''Old Goa'') is a historical site and city situated on the southern banks of the River Mandovi, within the Tiswadi taluka (Ilhas) of North Goa district, in the Indian state of Goa.

The city was established by the Bijapur Sultanate in the 15th century AD. After the Portuguese conquest of Goa, it served as capital of Portuguese Indian possessions, such as Mumbai/Bombay (Bom Bahia) territory and the state of Kochi/Cochin (Cochim), until its abandonment in the 18th century AD due to a plague. Under Portuguese rule, it is said to have been a city of nearly 200,000 people, from whence the spice trade was carried out across the Portuguese East Indies. The deserted city, containing churches and convents of outstanding architectural and religious importance, has been declared a World Heritage Site by the UNESCO. Old Goa is approximately 10 kilometres (6.2 miles) east of the current state capital of Panjim (Portuguese: Nova Goa, lit. ''New Goa'').