When Nature declined to provide any one of her own emphatic boundary-lines, such as a mountain-chain or a broad and deep river, to determine the frontier which should divide England from Scotland, she left a very delicate and difficult international question to be adjusted by the rulers of the two adjacent realms, so long as this single island of Britain should be divided into two distinct, and by no means necessarily friendly, kingdoms. An artificial line of demarcation, accordingly, had to be drawn, and was drawn, which was supposed to be accepted and recognised both to the north and to the south of it. Here and there, as if to show in the clearest manner possible the unsatisfactory character of a frontier such as this, to a tract of country the ominous name of “Debateable Land” was assigned by common consent. On either side of the frontier-line, again, and including all the “Debateable Land,” the “Border” stretched far away to both the north and the south; and, throughout its whole extent, it formed a decidedly exceptional territory, in which there prevailed a system of wild laws that were administered after a still wilder fashion: hence, whatever may have been the state of things between England and Scotland, and between the two sovereigns and the two nations, along the Border there flourished a chronic local warfare, duly distinguished by gallant exploits, desperate enterprises, and barbarous devastation, with the occasional variety of an expedition of sufficient magnitude almost to constitute a regular campaign, or the formal investment, and perhaps the storm and sack, of some important fortified castle.[19] The Borderers appear to have become so accustomed to this kind of life, that they looked upon it as their proper lot, and after a manner even regarded it with a kind of grim approval. Among them, doubtless, there were but too many who were thoroughly in earnest in their devotion to what may be styled the Border system—men “Stout of heart and steady of hand,” who, living in the constant expectation of some sudden assault, were both “good at need,” and ready and resolute at all times to take advantage to the utmost of every promising opportunity for successfully and profitably assaulting their hostile neighbours. In order to keep a check upon this predatory warfare, and to maintain something more than the semblance of a supreme constituted authority, certain warlike barons, intrusted with high powers as Lords Wardens, were established in fortified castles of great strength along the line of the Border, and in those northern districts of England which adjoined it. Of these early strongholds one of the proudest and the sternest was the Castle of Alnwick. [Illustration: _Plan of Alnwick Castle._]