The survey of early Slav history which I have attempted in this book covers roughly the period A.D. 500–1200. It is primarily a narrative describing how the various Slav peoples entered Christendom, moved by the currents reaching each of them from outside and guided by the great men who most furthered the transformation.

No one embarking on such a narrative could have the temerity to assert with Ranke's crude optimism that he would tell the story wie es eigentlich gewesen. This would be impossible even if our sources were many times more voluminous and more evenly distributed than they are. There are ‘probablys’ and ‘possiblys’ at every turn; there should be more. I have tried to avoid being tedious without being unscrupulous. The reader must always bear in mind that many passages are little better than construction laced with surmise. The few books in English which treat this period of Slav history often impart a spurious air of precision.

In a general survey of this kind discussion of every variant hypothesis at every step is ruled out in advance, but I hold it necessary to make clear to the reader what is relatively certain and what is not, and to give some account of rival theories at points of special importance. Even this required strict selection. Some parts of the story are better documented, some of wider historical interest, some of more particular interest to me personally. Therefore the degree of detail will be found to vary considerably, but not, I trust, to the detriment of the story as a whole.