In the years which have gone by since Werner Sombart called attention to the desirability of investigating the economic history of building, relatively little has been done in that direction with regard to medieval Europe as a whole though some notable contributions have been made in regard to particular buildings and countries. A major difficulty is the scarcity, especially for the earlier Middle Ages, of the kind of record which is essential. Archaeological and literary evidences, though useful, cannot by themselves do much more than indicate the kind of question which the inquirer must ask; for the answers there are needed accounts of the expenditure on building operations. Unfortunately, those relating to important buildings, such as large royal and ecclesiastical works in France during the early fourteenth century, have in many cases been lost. Large numbers, relating to buildings of various kinds in different countries, have survived sporadically; but probably the fullest series in existence is that relating to works carried out for the crown in England. This is the more valuable because it includes not merely summarised accounts, from which relatively little can be learned, but particulars, in some instances even weekly statements, giving the names of workmen with the amounts paid to them and similarly full detail relating to purchases. The ideal collection, which is rare, is that of which the London Bridge Accounts are a sample; these are particulars, extending from week to week or month to month over several centuries, an invaluable record of changes in wages and prices paid at the same undertaking.