Named after the plebiscite taken on October 21, 1860, that brought Naples into the unified Kingdom of Italy under the House of Savoy,[citation needed] the piazza is very close to the gulf of Naples and bounded by the Royal Palace (east) and the church of San Francesco di Paola (west) with its hallmark twin colonnades extending to each side.

In the first years of the 19th century, the King of Naples, Murat (Napoleon's brother-in-law), planned the square and building as a tribute to the emperor.

Soon after Napoleon was finally dispatched to St Helena, the Bourbons were restored to the throne, and Ferdinand I continued the construction but converted the finished product into the church one sees today.

[citation needed] In 1963, a municipal ordinance transformed the square into a public parking lot to cope with the uncontrolled increase of cars in the city.

[1] The square was thus disfigured (among other things, in addition to the car park there was also an extensive parking area for public transport buses close to the roadway, and even welcomed a large yard for the construction of the Rapid Tramway towards the end of the eighties) until in 1994, on the occasion of the G7 summit, the square was renovated, first replacing the asphalt of the roadway behind the Royal Palace with the more traditional paving stones, and then pedestrianizing it in its entirety.