The town of Alcúdia was used as refuge in many times of danger, as in the popular uprising of the Germanies when the walls played a key part. The noblemen of Mallorca took refuge in Alcúdia, while the uprising was put down by the troops of Emperor Carlos V. Once the uprising was stifled, the loyalty to the Emperor was rewarded in 1523 with the title of Ciutat Fidelíssima, among other privileges.

After the uprising of the Germanies, difficult years followed for Mallorca, including Alcúdia. The proximity to the coast, which was previously an advantage, became the scourge of the town. The feared corsairs disembarked and plundered the city time and time again, as in the attack which took place in Cap de Pinar in 1558.
The insecurity in the area and the flight of the owners to Palma led to a severe fall in population. In fact, the fall was so severe that in 1779, during the rule of Carlos III, the harbour was renovated to facilitate international trade with the goal of encouraging economic activity and at the same time repopulate the city.
All the same, the economy and population of Alcúdia did not flourish until the 20th century, when in 1957 an electric power station (GESA) was set up in the harbour in order to supply energy for the whole island.
The first tourists arrived in Alcúdia in the beginning of the 20th century but the boom of the tourism sector did not start until the 1970s, as in the rest of Mallorca. The large wetlands of l’Albufera were drained and large hotel complexes were built on them. In the 1980s, a new urban development boom led to a new wave of construction. At present, Alcúdia devotes itself entirely to the tourism industry. It has over 29,000 hotel places.

The commercial harbour of Alcúdia is specialized in the reception and supply of electric power to Mallorca and Menorca. On the other hand, many products arrive in Mallorca through the harbour of Alcúdia. At present, the population of Alcúdia has reached 16,000 inhabitants and the city has become the second area of development after Palma due to the significant economic activity which takes place here.

The city of Alcúdia and the archaeological site of Pol•lèntia were declared a historic-artistic site in the Decree 21/41 on 20 July 1963. In recent years several plans have been introduced to preserve and recover these areas. The Consorci de la Ciutat Romana de Pol•lèntia was created by the Balearic Government, the Consell de Mallorca and AlcúdiaTown Hall to boost its recovery.