On 11 November 1805, the Austrians fought a successful rear guard action at Valvasone on the Tagliamento River in which the 23rd and 30th Dragoons were present. Lacour led four regiments of dragoons in action at Flitscher-Klause (Bovec) on 19 November. General-major Heinrich Bersina von Siegenthal commanded two artillery pieces and 1,200 Austrians in the "De Ligne" Infantry Regiment Nr. 30. Because the action was fought in a mountain pass, the Austrians were able to hold off Lacour's column. Since no French officers became casualties, losses were probably light. The 23rd, 24th, 29th, and 30th Dragoon Regiments were the only units of that type with Masséna's army. Lacour's independent force eventually linked up with Michel Ney's VI Corps at Villach. Lacour participated in the Invasion of Naples in 1806. In March 1806, Mermet's cavalry division was organized with the 23rd and 24th Dragoons in the 1st Brigade and the 29th and 30th Dragoons in the 2nd Brigade, though no brigadiers were named.