In this book, the late Michael Costeloe has given us an excellent account of British investment, and investors, in early independent Mexico. Based on voluminous research in various depositories in Britain, the United States, Mexico and even Australia, and on sources such as company reports, personal letters, newspapers and the usual government records, as well as the available secondary literature, he has put together a remarkably complete picture of opaque endeavours in a turbulent period of Mexico's history, something of which the enterprises and investors of whom he writes could have only dreamed.

He begins by establishing what the British investor could know about Mexico in 1821, and why they would consider putting their money into such a distant and foreign country. There was in fact a good deal of information available, some of it highly reputable (from Humboldt, for example), some more hopeful than accurate. All reported on the riches of the country, which was welcome news, as the return of peace after the Napoleonic wars had led to lower interest on consols (consolidated annuities), long-term low-interest British government securities. This made the promised higher dividends from mining the country's legendary mineral wealth highly attractive, indeed necessary for many living on the interest from limited capital. In the circumstances of the early 1820s, the problem seemed to many such people to be more that of finding a suitable opportunity for new investments, rather than whether they were safe investments.

So people wanted to invest, and Mexico was alluringly there. Costeloe scrutinises the companies in which investors put their money, and follows their corporate fortunes. Most of the enterprises whose founding, working and fate he examines in careful, if qualified, detail (one of the great merits of the work is his examination of the sources and their limitations) failed – but slowly. They either survived, or came after, the Bubble of 1824–1826, and fed their shareholders spasmodic dividends and detailed, hopeful reports, which ensured that calls on shares were usually met, and that shares maintained at least some value on the stock exchange, before their painful liquidation occurred. And, mirabile dictu, he even finds one company that survived profitably into the twentieth century. This was the El Bote Mining Company, whose anonymity in a generally well-trawled field is doubtless explained by its being privately owned.

But for this exception, the rule was one of failure, as has been known since at least the second half of the nineteenth century. There was no Mexican equivalent of the Brazilian St. John d'El Rey Mining Company, though with a bit of luck – or more patience – the Real del Monte Company might have been one for British investors. Nor did a figure emerge equivalent to the Chilean ‘Nitrate King’, John Thomas North, with an individual fortune based on Mexican mining. The causes of the failure were many: poor management, misunderstandings with labour, natural disasters, turbulent relations with government at various levels and so on. However, Costeloe does point out the gains to Mexico from the investment, new technology and skilled manpower. So it was not all failure. Except to the shareholders.

One of the most valuable parts of a valuable book is Costeloe's consideration of the shareholders. Exhaustive research enables him to demonstrate in general terms who they were and where they lived. Though the numbers were weighted towards London, there were shareholders throughout the British Isles, male and female. And they came from the middle class: the author identifies doctors, lawyers, farmers, retired navy and army officers, clergymen, widows (and their unmarried daughters) and merchants, to give but some of the categories. Wealthier shareholders were bankers, brewers and stockbrokers, also very visible as directors. To some of these, he can give names, which enables him to discuss the speculative activities of a number of the shareholders. In general, he concludes that while there is no evidence of the deliberate ‘puffing up’ of the market in Mexican companies, it is equally clear that some individual shareholders did speculate, and that some did very well. But they were the exceptions; once the market settled down after the Bubble, there were no real opportunities for speculation; the best that could be hoped for was to sell on a (slightly) rising market. Those who stayed in for the long haul were to be disappointed.

Mining was only the most visible, and by far the largest, of the areas of British investment in Mexico, and Costeloe looks more briefly at some of the other areas. One of these was running the regional mints, and here profits were made: the Anglo-Mexican Mint Company was successful for nearly half a century. And there was always commerce. This was not organised in joint stock companies, and so does not appear as an investment, yet it seems clear that British firms and British merchants were the most successful in a very heterogeneous sector. Manning and Mackintosh in Mexico City are the most visible examples of this, yet they hardly appear in UK records. Indeed, it is in this area of non-mining activities that it is most clear that more research remains to be done, as the author makes clear.

This work is one of arduous empirical research, and generally the author keeps his analyses to the micro-matters he is discussing – why invest in Mexico, why move out of consols, why companies failed, and so on. This is the nature of the work, and to be accepted as such. However, Costeloe does revisit, sensibly if briefly, almost in a throwaway manner, the old question of informal empire, and whether it existed. He finds that it did not. So this excellent book, so complete in itself, leaves us with two avenues for further research and debate: the non-investment sector of British economic activity in Mexico, and the definition of informal empire.