The second corps, under the command of colonel Sierakowski, left, a few days before that of general Chlapowski, with the view, as we have also seen, to follow and observe the division of general Saken, who had been cut off by general Skrzynecki from the Russian guard, and compelled to remain on the right bank of the Narew. This corps consisted of two battalions of infantry of the 18th regiment, recently formed, amounting to 1,500 men, two squadrons of horse, of Plock, also recently formed, 250 in all, and two pieces of cannon. This corps, in the execution of its instructions, obtained several advantages over general Saken, near Stavisk. Colonel Sierakowski then advanced to the environs of the little town of Graiewo, where he took a strong position, and awaited the arrival of the corps of general Gielgud. The third corps, under the command of general Gielgud, being the second division, left the town of Lomza on the 27th of May. It was composed of 9 battalions of infantry, consisting of 4,500 men, 5 squadrons of cavalry of 600 men, 160 sappers, and 24 pieces of cannon. The total force of these three corps was then as follows: _Artillery_, 28 pieces. _Infantry_, 6,350 men. _Cavalry_, 1,300. Besides these forces, which were detached from the grand army, there were formed in Lithuania, several regiments of infantry and cavalry, which we shall designate in the sequel, but which did not commence active service until the battle of Wilno. To return to the main army. Such was the rapidity with which the operations of general Skrzynecki upon the Russian guard were executed, that, as we have said, he was on his retrograde march, after having driven that guard beyond the frontiers, before marshal Diebitsch received intelligence of his operations. It was then that the Russian commander, having no hope of saving the guard, conceived the plan of attempting, by a prompt diversion towards Ostrolenka, to cut off the communication of our army with Warsaw. [_See Plan_ XXIX.] With this view he evacuated his position at Sucha and Mordy (_o_), passed by Sokolow, crossed the river Bug at Granne (16), entered into the Russian province of Bialystok, passed through a corner of this department on the 24th of May, and crossing the little river Nurzec (R), at Ciechanowiec (17), entered again into the Polish territory, and occupied the road of Czyzew (18) and Zambrowo (19). Without any delay he pushed his advanced guard as far as Czyzew. General Lubinski was then at Nur. This little town was at the same distance from Ostrolenka as Czyzew, but the communications with Ostrolenka were more difficult, Czyzew being on a principal road. The enemy, observing this circumstance, and taking it for granted that Lubinski was cut off from the main army, sent an aid-de-camp with a flag of truce to summon him to surrender.[60] This summons was rejected.