Cathedral of the Sea, by Ildefonso Falcones, trans. Nick Caistor

Rich and racy homage to old Catalonia

In the 14th century, Catalonia's ships dominated the western Mediterranean. Its merchants opened offices in every port to Alexandria and built fabulous mansions on Barcelona's Carrer Montcada. But the empire was overstretched. Mid-century, plague halved the population. The king taxed the Jews to finance his wars and his nobles ravaged the countryside to feed the city. Peasants starved. Ildefonso Falcones's adventure novel is set just at this moment of Catalonia's greatest glory, when ostentatious wealth is barely papering over imminent collapse.

Barcelona's Santa Maria del Mar church (the cathedral of Falcones's title) was built in 54 years in this century, so quickly as cathedrals go that it is all in one style, a high, spacious, unadorned Gothic. "Its only decoration will be the light of the Mediterranean," as Falcones writes. His hero, Arnau, sees the cathedral start and lives to celebrate its completion. Some of Falcones's best pages describe the construction: the carrying of the stones from the Montjuic quarries, the raising of the giant keystones.

Just as the cathedral is a great enterprise, Arnau is a great man. Born a serf, he survives perils, saves Barcelona from Pedro the Cruel of Castile, and is made a baron. His evil enemies plot to have him imprisoned by the Inquisition. His lifelong goodness to his fellow-workers, to clients and to outcasts such as the Moors and Jews leads to a near-revolutionary uprising to free him.

Cathedral of the Sea is a formula adventure novel, its huge sales augmented by the glamour of Barcelona's reputation. It contains everything such a book requires: the evil lord raping a serf on her wedding night, summary hangings after a bread riot, long-suffering Jews, demented friars, cruel treatment of women, the vicious Margarida Puig, the beautiful and sexually voracious Aledis.

It is more than just a formula novel, though. Falcones is a lawyer, and the complex plot turns on legal and financial manoeuvres that give an idea of medieval systems rarely found in a historical novel. Passionate in explaining 14th-century Barcelona, he draws convincing pictures of its architecture and culture, right down to basics such as the sewage stream (where the modern-day Ramblas now runs).

The plot too often relies on outrageous coincidence; the style rarely rises above the ordinary; good Arnau is too good. Unlike the best Stevenson or Dumas adventures, the characters are one-dimensional, without contradictions. Little of this matters once within the story. Cathedral of the Sea is an exciting, very readable adventure novel, enriched by realistic descriptions of medieval life, work, finance and politics.

Michael Eaude's 'Catalonia' is published by Signal