Celebrating someone's 200th birthday is an ambiguous business. It reminds everyone how long the birthday boy has been in the grave - or, in Victor Hugo's case, in a stone sarcophagus in the bowels of the Pantheon in Paris, next to Emile Zola. It also begs the question: are they still important?

A century and a half ago, Hugo seemed bound for obscurity. Europe's greatest poet, the leader of the French Romantics, had opposed the coup d'état that brought Napoleon III to power. He escaped from Paris, disguised as a worker. Soon afterwards, he sailed for Jersey with his family and his mistress. For the next 18 years, Hugo lived in the Channel Islands. These "bits of France that fell into the sea and were picked up by England" turned out to be Hugo's ideal setting. Sandwiched between the imperial powers, he broadcast to his international audience. Democratic movements from Mexico to Serbia hailed him as a hero. Hugo had found his intellectual home. His political dream was the confederation he called "the United-States of Europe". He even suggested a single currency.

If things had moved more quickly, we might have been looking forward to a referendum on joining the hugo.

Hugo's barnstorming diatribe against the new dictator, Napoleon le Petit, was smuggled off the island in sardine tins, walking-sticks and underwear. Pages printed on onion paper were rolled into cigars and made into balloons. Plaster busts of Napoleon Ill arrived at the Gare du Nord containing copies of Napoleon le Petit.

Hugo is often depicted as a Victorian De Gaulle, enjoying British hospitality and sneering at his hosts. But he had good reason to be unhappy. When the Crimean war broke out, the British Government decided that Napoleon III was a good thing after all. Hugo was now an international embarrassment. Palmerston sent agents provocateurs to the island. A Scotland Yard detective peered through the Hugos' windows and sent back ominous reports on the "anarchists": "They use in their speeches foul language, taking the most dreadful oaths, issuing threats against all the Kings and Queens."

In 1855, Hugo and his fellow refugees were expelled from Jersey. Fortunately, Guernsey, which was semi-independent, welcomed the exiles. As they sailed from St Helier, a paid mob shouted, "Down with the bloody Reds!"

In the circumstances, Hugo's remarks about the English ("a noble race of brutes") were quite moderate. His first words on seeing London were "How do we get out of here?" Like most foreign visitors, he hated English Sundays when "even the dogs stop barking". A land where public toilets were adorned with the bizarre inscription, "Please adjust your dress before leaving", was not, in Hugo's view, a healthy, grown-up sort of place.

Teasing the English was irresistible. On a trip through southern England, he shared a railway carriage with two ladies. It must be inconvenient, they supposed, not to know any English. Hugo replied, "When England wishes to converse with me, it will learn to speak French." (He must have known there was little danger of that.) In fact, he had good advice for anyone wishing to speak English like a native: simply miss out all the vowels. "An excellent method for pronouncing English names is not to pronounce them at all. Thus, instead of Southampton, say Stpntn".

Views of Hugo in England are coloured by contemporary documents. French propaganda portrayed him as a disappointed megalomaniac. A school text book described the nation's greatest poet as "an escaped convict".

At Westminster, Robert Peel Jr responded to Hugo's condemnation of the carnage in the Crimea with the smug ungenerosity that is still shown to refugees: "If miserable trash of this kind is to be addressed to the English people by foreigners who find a safe asylum in this country, I would appeal to the noble Lord the Rome Secretary whether some possible step cannot be taken to put a stop to it"

But beyond Whitehall there was real sympathy. When Hugo was driven off Jersey, there were protest meetings from London to Glasgow. Hugo was a friend of leading Chartists, and his campaign against the death penalty had an effect, even in England. Palmerston was disturbed by Hugo's description of an execution on Guernsey and called for reform.

And, of course, the "miserable trash" that Hugo produced on British soil includes some of the finest works of European literature: Les Miserables, and three novels that were bestsellers in Britain well into the 20th century: Toilers Of The Sea, The Laughing Man and Ninety-Three.

These wonderful stories are enough to show that Hugo is still important. But the King of the Channel Islands is also a vivid reminder that to be a European is not to lose one's national identity.

· To order a copy of Victor Hugo by Graham Robb for £8.99 inc UK p&p, call the Guardian book service on 0870 066 7979.