it by the French of the news of the fall of Namur.  On account of this delay not only was the extreme of the line which the British held immediately threatened with outflanking, but it still lay somewhat forward of the rest of the force.  It was in danger of being turned round its exposed edge C, not only because it lay on the extreme of the line, but also because, instead of occupying its normal position, AB, which it would have occupied had the retreat begun with all the rest, it actually occupied the position CD, which made it far more likely to be surrounded than if it had been a day’s march farther back, as it would have been if the French Staff work had suffered no delays.

[Illustration:  Sketch 54.]

There lay in the gap formed by this untoward tardiness in the British retirement, at the point M, the fortress of Maubeuge.  It was garrisoned by French reserves, or Territorial troops, not of the same quality as the active army, and its defensive power was, even if the old ring of fortress theory had proved sound, of very doubtful order.

The French 5th Army being no longer present to support the British right, but having fallen back behind the alignment of that right, General Sir John French had no support for what should have been his secure flank save this fortress of Maubeuge, and it will be evident from the above diagram that the enemy, should he succeed in outflanking the British line, would compel it to fall back within the ring of forts surrounding Maubeuge.  To avoid destruction it would have no alternative but to do that.  For, counting the forces in front of it and the forces trying to get round its back, it was fighting odds of two to one.

Maubeuge was a stronghold that had played a great part in the revolutionary war.  Its resistance in the month of October 1793 had made possible the French victory of Wattigines, just outside its walls, and had, perhaps, done more than any other feat of arms in that year to save the French Revolution from the allied governments of Europe.  It was, indeed, full of historic memories, from the moment when Caesar had defeated the Nervii upon the Sambre just to the west of the town (his camp can still be traced in an open field above the river bank) to the invasion of 1815.

But this role which it had played throughout French history had not led to any illusion with regard to the role it might play in any modern war; and at the best Maubeuge, in common with the other ill-fortified points of the Belgian frontier, suffered from the only error—­and that a grave one—­which their thorough unnational political system had imposed upon the military plan of the French.  This error was the capital error of indecision.  No consistent plan had been adopted with regard to the fortification of the Belgian frontier.