This compilation concerns account books, not books on accounting. Most of the essays analyse the account book(s) of a single person or business. In each case the account book(s) demonstrate the presence of, at least, elements of double entry. The essays come in pairs, beginning with Geoffrey Lee's paper on Florentine bank ledger fragments of 1211, some of the earliest relics of Italian bookkeeping. Subsequent papers trace the development of double entry over the centuries until 1786 when full double entry was achieved. There are papers from the UK and USA which illustrate the use of balance sheets, valuation techniques and the accruals convention as well as papers which analyse the causes of the development of double entry, using the evidence of others.