The Russian forces at this point were led by General Russky, among whose commanders was Radko Dmitrieff, of Balkan War fame. Both of these generals are to be counted among the greatest Russian leaders and they were especially expert in everything that pertained to fortresses and their defense. As wonderful as the German military machine had proven itself, as severe as their often repeated offensives were, as superior as their supply of artillery and munitions was both in quality and quantity, Russky and Dmitrieff proved a good match for them all. The possession of Dvinsk at that particular moment would have meant an almost inestimable advantage to the Germans, just as its loss would have been apt to mean the complete rout of the Russians. For once the line broken to a sufficiently great width at that point, all the Russian forces having their basis on Petrograd, Smolensk, and Moscow might have been turned completely.
This supreme importance of Dvinsk was understood equally well by both sides. On the part of the Germans this understanding resulted in unceasing attacks by all available means and forces, while the Russians on their part were prepared to defend their positions with a stubbornness and determination unequaled by the case of any other fortress with the possible exception of Riga and Rovno. The harder the Germans drove their armies against Dvinsk the harder the Russians fought to repulse them. The latter were greatly assisted in this by the fact that strong reenforcements had been sent to this crucial point from Petrograd and from other interior points. Still more important was the beginning of considerable improvement in the Russian supply of guns and shells. Even though, in that respect, Russky was undoubtedly still far behind his German opponent, Von Hindenburg, yet he was at that moment in a much better position than any other Russian general. Dvinsk had to be held at all costs--the Russian General Staff apparently had decided--and to Dvinsk, therefore, were sent all available guns and munitions.
Originally the fortress of Dvinsk was far from being up to date or particularly effective and imposing. It consisted of an old citadel which, it is true, had been improved considerably; but even then its outworks extended hardly farther than a mile beyond its own range. As soon as General Russky assumed command he began feverishly to improve these conditions. In this undertaking he was greatly assisted by the nature of the countryside surrounding Dvinsk. Immediately to the northwest, west, south, and southeast the River Dvina formed a strong line of natural defense. Beyond that was a region thickly covered with small and big lakes, which swung around Dvinsk as a center, in the form of an immense three-quarters circle, starting to the south of the Libau-Ponevesh-Dvinsk railroad and stopping just west of the Dvinsk-Pskoff-Petrograd railroad. The diameter of this circle varies from thirty miles to sixty. The ground between these lakes is swampy in many places, difficult of approach, and comparatively easy to defend even against superior forces, especially because most of it is not entirely flat, but interspersed with hills and woodlands.