I don't know if I mentioned to you that I don't want horses that are less than 5 years old, which is a hindrance in campaigns starting in November. The hunters, hussars, and even the dragoons cannot find horses of the required size; they must buy smaller ones. They will thus show themselves easily, very easily, in France, while otherwise, it would be impossible. They will have 5-year-old horses in good condition, and they will even save money, allowing them to buy more. Write a circular to all the units and be very active in all this. Maintain correspondence with the depots, and every 8 days let me know the number of horses that have arrived. If the depots have more men than the money I have granted, they should produce 2 horses; authorize them to buy new ones to be fully prepared for war. I am sending you a decree to form the 5th squadron of carabiniers and cuirassiers in accordance with the decrees of August 31. It is therefore necessary to urgently procure horses so that the 4th squadron, which is at the depot, can join the army at the beginning of November. The fifth squadrons should be formed with men selected from officers who are on leave; there are still very good ones among them. Just be careful to appoint officers who are returning from the main army. This does not unfairly weaken it. On this, I pray to God to keep me in Mayence on September 30, 1806.“
In Napoleon's campaigns of 1805 (against Austria and Russia), 1806 (against Prussia), and 1809 (again against Austria), Mainz was the most important French assembly point..