As at a school, the calibre of the principal was all important. At the centre of the story are two rivals 'for the town's very soul': the bon vivant burgess Matthew Chubb, 'the best housekeeper in town', and John White, an Oxford Calvinist with a mission who arrived as rector in 1605. David Underdown's thesis is that John White and a powerful 'spiritual cousinhood' systematically eased Chubb's old guard out of position, and transformed the easygoing little country town into something approaching an urban Utopia. The catalyst was the 'fire from heaven' of the title, a blaze that started in a tallow shop and devastated the place in 1613. As many as 170 houses - half the dwellings in the town - were destroyed. Underdown claims that the physical and financial impact of the fire was less striking than its emotional impact, 'a sort of spiritual mass conversion'.
Certainly when John White died 43 years later, he left Dorchester a reformed and godly community. Receipts from charitable collections soared, and poor relief doubled. A hospital was founded, not for the sick but to educate children up to the age of 21, training them for jobs. An ingenious system of financing meant that the proceeds of a municipal brewhouse paid for this and many other urban good works. Not everyone liked the new regime. 'A plague of God on the slaves of Dorchester,' shouted a Cerne Abbas man arrested for drunkenness in 1634, and Chubb did what he could to maintain old customs such as May Day dating and travelling players.
But the royal government continued its fatally alienating moves. Ship Money was about as unpopular as our own beloved poll tax, and the poor paid it 'like drops of blood'. When the time came to take sides, there was no doubt where Dorchester stood. Clarendon's great History of the Rebellion described the place as 'the most malignant town in England, entirely disaffected to the King'. Underdown shows us the Civil War through local eyes, a matter of repairing the town's drum, putting new shutters on the town hall, re-feathering arrows and trundling barrels of gunpowder to safety. The first engagement is a fiasco, with men sensibly running away as soon as they possibly can.
The ambiguity of local reactions to news of the King's execution reflects the mixed feelings even of puritans to regicide, and the charitable Utopia did not survive John White's death and the Restoration. Graft and gain were again the norm by the end of the century when the first coffee houses opened, and Daniel Defoe found the dissenting preacher amicably taking tea with the Anglican clergy.
Throughout the book, the personalities who capture the imagination are not the flamboyant heroes and villains of H E Marshall's inimitable Our Island Story - Stafford, Cromwell and the stiff-necked Stuarts - but society's leavings: Elinor Galpin, a witless destitute hanged for killing her 10-day-old baby, itinerant puppeteers and a showman with a camel, a quarrelsome scold called Mary Tuxderry, sentenced to be 'plounced' in the pond 'when the weather is warmer'.
There is ample fodder here for all manner of interests, and addicts of family history in search of urban background for their ancestors will relish every word. But there is also bias of a sort. 'Historians are the prisoners of their sources,' admits Underdown, and since 17th-century Dorchester did not have a Pepys or a Kilvert to paint a rounder human picture, there is inevitably an over-emphasis on council chambers, parish registers and county courts. It's a pity Hardy didn't live a little earlier, really. I'm sure he would have made something of Elinor Galpin and Co.