Visitors to London often ask: "Where's the centre?" They're surprised to find locals responding: "Umm, which centre do you mean? If you're talking entertainment, you probably mean Soho, if government Westminster, and business the City (although with Canary Wharf coming up fast).

It is a confusion that has historical roots. For "London" well into the early modern period had a specific meaning, the City of London, enclosed within the walls drawn more or less along the route established by the Romans. It had suburbs, like Clerkenwell and Whitechapel, relatively lawless areas that lived in uneasy symbiosis with the tightly controlled city.

Then there was the other city - Westminster, an entirely separate, if less clearly defined, entity. By 1662 it was in the eye of one observer "the greatest City in England next London, not onely in Position, by by the Dimensions thereof ..." It from 1601 had its own coat of arms, and there were three attempts between 1585 and 1633 to establish it fully as a legal entity equal to the City.

Recent historical work has done much to recover Westminster's medieval history, through the records of the abbey, but says J.F. Merritt, author of The Social World of Early Modern Westminster: Abbey, Court and Community: 1525-1640, the early modern period has disappeared into more general discussions about the development of the West End, or the "western suburbs" of the City.

He seeks to recover Westminster's history through the records of its two main parishes, St Margaret's, centre of the medieval vil, and St Martin in the Field. Through extensive work in their records, he explains how each very different church - one long-established, the other relatively new and fast-growing - dealt with all of the turmoil of the Reformation.

The results are somewhat surprising, for it seems that St Margaret's, despite its close proximity and links to the Royal court, was highly resistant to "Protestant" reforms, and only adopted them under pressure, while St Martin was more flexible.