In his time, Giuseppe Garibaldi seemed Christ on horseback. He campaigned for liberty and justice wherever they were threatened. He was a freedom fighter in Latin America before returning as a hero to lead the battle for Italian unity. His 1,000 red-shirt volunteers defeated a Bourbon army of 20,000 to capture the Sicilian capital, Palermo, and ignite the struggle that led in 1861 to Italian unification.

This brought him worldwide recognition as a courageous, dashing warrior uninterested in political manoeuvring. He was colourful, too, attending parliament in Turin dressed in a poncho and his trademark red shirt. Moreover he was not venal. In 1860, when he stepped aside to ensure Vittorio Emanuele became king of Italy, he retired to the Sardinian island of Caprera, taking with him only seeds, coffee, sugar, macaroni and dried cod.

His life is an oft-told adventure that took the seaman as far afield as Odessa, China, Tasmania, New York, Peru and Uruguay and there is now a revival of interest in Garibaldi, with at least two books being written on him.

Daniel Pick, a psychoanalyst who teaches cultural history at the University of London, doesn't provide a new biography of the 'hero of two worlds'. Rather he examines Garibaldi's attempt, at the age of 68, to ensure the Tiber river was diverted around Rome to avoid its periodic flooding of the city.

In 1875, five years after the capital was transferred to Rome, Garibaldi returned from Caprera to the city to campaign strenuously, but ineffectually, to divert the unruly river and replace it with a Parisian-style boulevard. Pick claims that Garibaldi's campaign was fuelled by the obsessions he tries to identify. On the way, he provides interesting information on the yearly ravages of malaria in Rome and the surrounding countryside, which were attributed to miasmas rising from stagnant water rather than to mosquitoes.

He also describes the imaginative hold Rome exercised on many, not just as a city, but for its symbolic and mythological overtones.

He seeks to link these overtones to the alleged obsessions of Garibaldi caused partly by his mixed feelings of love and hate for Rome and also by the death of his beloved wife, Anita, when they were pursued after being forced to leave the city in 1849. Maybe these experiences led to obsessions; maybe not. The argument isn't persuasive because Pick doesn't sufficiently link Garibaldi's behaviour to the cultural myths he evokes.

An attractive aspect of Garibaldi was that, after unity, he didn't rest on his laurels nor did he want to militarise Rome as did many regular army people. He looked to the future. He wasn't a professional soldier, but a go-getter. He even wrote successful, anti-clerical, soft porn novels.

But, at the same time, Garibaldi was bitterly disappointed by the grasping, unidealistic reality of post-unity Italy. Pick maintains that Garibaldi's Tiber-diversion scheme was both an ideal battle to transform Rome and a quixotic campaign that Garibaldi knew would redound to his credit even if failure was likely.

Pick is fair-minded in handling controversial issues, but appears to have strung out what should have been an article to book length. He doesn't justify his use of 'obsessions' in the subtitle and the title Rome or Death refers to the unity struggle rather than the Tiber campaign.

His psychobiographic reflections have too much psychology without sufficient grounding in Garibaldi's life and even lack just plain facts such as that Tiber floods are due to a tributary joining it near the city. One suspects the scheme was just the last gasp of a pigheaded campaigner.

Anyway, it's hard to sympathise with Garibaldi's campaign now that malaria has disappeared and success would have deprived the city of its river and given it instead yet another road choked with cars.