In this paper we analyse the characteristics of Spanish firms during the nineteenth and the first third of the twentieth century, on the basis of the contributions made by a new discipline, namely Business History. The historical behaviour of firms is studied by reference to a broad range of sectors and different regions, although emphasis is placed on those sectors and regions that enjoyed the greatest development. The results of recent research undertaken within the field of Business History are examined by adopting the perspectives and concerns of those whose present day interest is to analyse the size, organisation, behaviour, strategies and results of Spanish firms, as well as their international competitivity. After describing the historical characteristics of Spanish firms and discussing the most broadly accepted theses which explain their small scale and family character (such as the scarcity of entrepreneurs, the legacy of the Ancient Regime or the limited size of the markets), others explanatory causes are considered, namely the personal links between businessmen in the different industrial activities; transaction costs and vertical integration; product diversification strategy; financial restrictions; the tendency towards collusion and the frequency of lobbying practices; the importance of foreign and Stateowned companies and the late adoption of a scientific model of business organisation. Finally, we offer some speculations on the relationship that exists between the business factor and the political, economic and social environment in the Spain of that epoch.

Keywords: business history, economies of scale and scope, foreign companies, State-owned enterprises.