The fight for freedom began in the 1940s as India inched closer to independence from British rule. But Goa remained a Portuguese colony until 1961, straining relations between India and Portugal as the former's support for the anti-colonial movement in Goa grew. In 1955, India even imposed an economic blockade on Goa.
In 1961, the Indian army invaded the state after the Portuguese fired at Indian fishing boats, killing one fisherman.
After 36 hours of air, sea and land strikes by the army, General Manuel Antonio Vassalo e Silva, governor general of Goa, signed the "instrument of surrender", handing over Goan territory to India.
Supriya Vohra hears from Goans about the days leading up to liberation.
Higino Emidio Rebelo, 71, hotelier
Vasco, where we lived, was a trading port. After the Indian government imposed an economic blockade on Goa, our provisions would be imported from across the world - potatoes from the Netherlands, wine from Portugal, vegetables and rice from Pakistan, tea from Ceylon [now Sri Lanka], cement from Japan, steel from Belgium. They would arrive in Vasco and then travel to different parts of Goa.
I remember the morning of 17 December when we heard that a bridge was bombed [by Portuguese troops, to hinder the Indian army advance]. My father sent us to my mother's maiden home, 30km (19 miles) south of Vasco.
When we returned some days later, we found that the Indian military had taken over our building.
The governor general was a man of first class character. When he visited Goa in 1983, we felicitated him with open arms.
We Goans have always believed in an environment-friendly lifestyle and economy. But things have changed in the last few years. There are plans to import more coal into the state, which will cause more pollution. Our rivers are being nationalised to carry cargo. No one is against development, but this isn't progress.
Libia Lobo Sardesai, lawyer
After India got independence in 1947, I joined the Goan Youth League. I always had a fire for Goa's freedom in me. After 1955, due to the economic blockade, Goans had no access to any outside news or information. It became imperative to expose Portuguese propaganda through a clandestine method which took the shape of an underground radio programme.
Vaman Sardesai [who she later married] and I started the station, broadcasting every morning and evening in Portuguese and Konkani [the local language]. The Voice of Freedom station was run from forests bordering Goa between November 1955 and December 1961.
It boosted the morale of Goan people.
It was not an easy life for us, but we were committed to our cause. We did not know how long we would have to go on - all we knew was that we must keep giving Goans information and inspiration.
The Portuguese army was not happy, and they tried to track us down. Thankfully, they couldn't.
On 15 December 1961, India's then defence minister, Krishna Menon, used our programme to send a message to the Portuguese army to negotiate. We repeated the message every hour throughout the next day. The Indian army entered Goa when they received no response from the Portuguese.
When I heard the news that the Portuguese had surrendered, it was the happiest moment of my life.
I felt I must go up in the skies to announce Goa's freedom from Portuguese rule after 450 years. In fact, we did that by dropping leaflets and making announcements while flying in a plane over Goa for two hours.
Goa was liberated for progress. But today, in the name of progress, the state is being vandalised.
Damodar Mauzo, 73, writer
When I was 12, I had to perform a religious ceremony at my home. We had photos of national leaders - Mahatma Gandhi, India's first prime minister Jawaharlal Nehru, independence leader Subhash Chandra Bose. There was also a photo each of Buddha and Jesus Christ.
My father invited Portuguese officials stationed in my village. He was advised by his friends to remove the photos of Indian leaders because he might be suspected of being a nationalist. At the time, most Hindus were considered nationalists, although there were many Christians fighting for Goa's freedom.