The origins of this book are both personal and academic. In 1975, I published a study of the first federal republic of Mexico which covered the years from 1824, when the republic was founded, to the middle of 1834, when it began to be dismantled. My interest in those years arose from a desire to know what were the politics, issues, personalities and, indeed, the events which had brought Mexico to the verge of political anarchy so soon after emancipation from Spain. After trying to guide undergraduates through the bewildering array of revolts and political factions, it was obvious that the existing literature was inadequate. Basically the same motives brought me to the following decade, from 1834 to 1846. Having tried a monarchist form of government with the short-lived Iturbide empire and then the federal republic, Mexicans chose to create a centralized republic with power firmly vested in national authorities located in the capital. Again, I wanted to know why they did so, who were the political and military leaders who brought about the change, what were their hopes, what pressures and tensions they faced and, in particular, why the chronic instability of the earlier decade continued unabated with the same myriad conflicting ideas, issues, factions and revolts. In short, my objective with the present work has been to write a reasonably detailed account of the centralist decade, a period which Professor Vázquez has correctly labelled recently the ‘forgotten years’ of Mexican history.