The first Roman invasion of the Iberian Peninsula occurred in 219 BC. Within 200 years, almost the entire peninsula had been annexed to the Roman Empire.
The Carthaginians, Rome's adversary in the Punic Wars, were expelled from their coastal colonies.
The Roman conquest of what is now part of modern day Portugal took several decades: it started from the south, where the Romans found friendly natives, the Conii.
It suffered a severe setback in 194 BC, when a rebellion began in the north. The Lusitanians and other native tribes, under the leadership of Viriathus, wrested control of all of Portugal.
Rome sent numerous legions and its best generals to Lusitania to quell the rebellion, but to no avail — the Lusitanians gained more and more territory.
The Roman leaders decided to change their strategy. They bribed Viriathus' ambassador to kill his own leader. Viriathus was assassinated, and the resistance was soon over.
Rome installed a colonial regime. During this period, Lusitania grew in prosperity and many of modern day Portugal's cities and towns were founded.
In 27 BC, Lusitania gained the status of Roman province. Later, a northern province of Lusitania was formed, known as Gallaecia, with capital in Bracara (today's Braga).
As with the Roman names of many European countries, Lusitania was and is often used as an alternative name for Portugal, especially in formal and literary or poetic contexts.
The 16th century colony, which would develop into Brazil, was named Nova Lusitânia ("New Lusitania").
In common use are such terms as Lusophone, meaning Portuguese-speaking, and Lusitanic, referring to the Community of Portuguese Language Countries — once Portugal's colonies and presently independent countries still sharing some common heritage.