Short answers, pulled from the story.
Diu is a medieval fortified town on a small island off the Gujarat coast, known for its Portuguese-era fort, Baroque churches, and Portuguese colonial architecture. It was a Portuguese possession from 1535 until 1961, when Indian military forces incorporated it under Operation Vijay.
Diu became part of India on the 19th of December 1961, when Indian military forces occupied the island under Operation Vijay. The operation brought overwhelming land, sea, and air power to bear on the enclave for 48 hours before the Portuguese garrison surrendered.
The Battle of Diu in 1509 pitted Portugal against a coalition that included Mamluk forces from Egypt, Venetian and Ragusian merchants, the Zamorin of Calicut, and the Sultan of Gujarat, Mahmud Begada. The battle was fought at Diu, an important port on the Arabian Sea trade routes.
Four languages are spoken in Diu: Gujarati, Hindi, English, and the Diu Indo-Portuguese Creole. The creole developed from contact between Portuguese settlers and local communities during the centuries of Portuguese rule.
The Diu Fort was built in 1535 and maintained an active garrison until 1960. It was selected alongside the Basilica of Bom Jesus in Old Goa as one of two Indian entries in a list of seven wonders drawn from 27 monuments built across 16 countries during the era of Portuguese colonial rule.
Diu was reported in April 2018 to have become India's first city to run on 100 percent renewable energy during the daytime.