The umbrellas were out along with the flags in Rome, as Italy celebrated its 150th birthday on Thursday. But the show of unity could not hide the deep divisions that run through the country.

The weather reflected the occasion: applause for the president Giorgio Napolitano, who invoked the spirit of national unity “whatever the battles between us”; jeers for the prime minister Silvio Berlusconi, a man who’s concept of unity is encapsulated in the expression “bunga-bunga”.

Far to the south, on the island of Lampedusa, the sun shone in a clear blue sky, but the flags were at half-mast. The celebration turned into a furious protest at the lack of help from the Government and the EU to cope with the influx of refugees from North Africa. The tiny island 70 miles from the Tunisian coast has already received more refugees in six weeks than its entire population of 4,500. It was only as a result of local protests that the Government consented to re-open the (inadequate) refugee camp on the island.

“Why no camps in Padania?” read one banner – a sarcastic reference to the name chosen by the right-wing Lega Nord for their proposed breakaway region in the north.

For the Lega, of course, unity is a dirty word, although it does not stop them taking part in Berlusconi’s corrupt, degrading regime. Most of their members boycotted Napolitano’s speech to parliament. Some of their mayors in northern towns such as Lesmo, just outside Milan, attempted to boycott the national holiday as well, provoking a patriotic backlash from local people.

In truth it wasn’t much of a holiday, and the government has decreed that remembrance day – 4 November – will not be a holiday this year, so it seems that even the anniversary of the founding of the nation does not merit an additional day off.

And that two-faced approach in a way symbolises the anniversary itself.

17 March 1861 was the day Italy became a nation. It was also the day Italy became a kingdom. Region by region Italians had voted overwhelmingly to be part of the new nation – 426,000 in Emilia-Romagna, 366,000 in Tuscany, 432,000 in Sicily, 1.3 million in the kingdom of Naples. To this day you can see those votes carved on tablets of stone on town halls up and down the country.

Yet when it came to the first parliamentary elections in January 1861, only 420,000 citizens had the right to vote, out of a population of around 26 million. Just 239,583 voted, and only 170, 567 valid votes were cast – and of those more than 70,000 were state employees. 85 members of the new parliament were princes, marquises and dukes.

Bastard-born, the new kingdom imposed a highly-centralised regime and heavy taxation. It was largely thanks to the revolutionary hero Giuseppe Garibaldi that the new nation was able to be properly unified, with the liberation of the north east from the Austrian Empire in 1866 and finally the end of the Papal State in 1870. Garibaldi and his followers also led the agitation for democracy which gradually led to the extension of the franchise.

Vittorio Emanuele, the first king, died peacefully. His monument is the giant temple of white marble, topped by the Chariots of Unity and Liberty, that dominates the centre of Rome along with the Colosseum.

Liberty, like Unity, was hard won.

Italy’s second king Umberto was shot dead by the anarchist Gaetano Bresci in 1900 in revenge for the massacre of over 100 workers in Milan during a general strike two years earlier. His son, again Vittorio Emanuele, lasted until 1946 – through the First World War, Mussolins’s seizure of power, Italy’s imperial adventures in Africa and the Balkans, Italy’s alliance with the Nazis, and finally the allied invasion and the national uprising that defeated fascism and the Germany army.

That victory, celebrated each year on 25 April, spelled the end of the monarchy as well as fascism. One year later, on 2 June 1946, Italy voted for a republic in the country’s first fully democratic elections, with women allowed to take part for the first time.

It was a vote that split the country north and south, but that day at least is commemorated by a permanent public holiday, the Festa della Repubblica.

On 2 June this year, Berlusconi is due to hold a further event celebrating national unity, a reception for foreign leaders – always assuming he is not in court.