Of the IIIrd Army, General von Rheinbaben, on the other hand, occupied with the three Brigades of the 5th Cavalry Division Courtlain, Brou, and Chartres, strengthened by five battalions of Guard Landwehr and four batteries. A letter from the Chief of the General Staff at Versailles had pointed out that this cavalry might probably be employed with great success in attacking the flank and rear of the enemy's retreating columns, and the Crown Prince had already given orders that it should push forward by way of Brou in full strength on the 15th. Contrary to these orders, the Division obeyed a subsequent order which reached it on the 16th from the Grand Duke, under whose command the Division had not been placed, to take up a position on the Yères.
On this day patrols had found the roads open to Montmirail and Mondoubleau, except for French infantry in front of Cloyes, which retired after a short fray. On the left, a connection was opened with the 4th Cavalry Division. On the 17th, the 12th Cavalry Brigade entered Cloyes, already evacuated by the French; on the 13th it advanced on Arrou, and only General von Barby (commanding the 11th Cavalry Brigade) marched on Droue with a force of all arms, where he surprised the French at their cooking, and carried off much booty.
On the 18th, the 12th Brigade did make prisoners of a few stragglers there, but the other two brigades only made a short march to the westward to La Bazoche Gouet and Arville, whence the enemy had quite disappeared. To the south of Arville a battalion of the Guard Landwehr drove the French infantry out of St. Agil.
With this the pursuit ended on the 19th. The Division retired on Nogent le Rotrou by the Grand Duke's desire, and subsequently undertook the observation of the left bank of the Seine at Vernon and Dreux.
The Grand Duke's Detachment left its quarters on the Loir on the 21st. The 22nd Division occupied Nogent le Roi, and the 17th Chartres, till the 24th. The 4th Bavarian Brigade rejoined its own Corps at Orleans.
During the remainder of December only the Xth Corps had any fighting, it having been detailed to keep watch beyond the Loir from Blois and Vendôme.
Two brigades were set on march towards Tours on the 20th. On the further side of Monnaie they met the newly-formed troops of General Ferri-Pisani, 10,000 to 15,000 strong, which were advancing from Angers and had passed through Tours.