Anno Thirteen: The Transition of the Two Westphalian Hussar Regiments under Colonel von Hammerstein and Major von Pentz to the Flags of the Allies in the Night of 22–23 August 1813 (Marburg: Koch, 1813) is a contemporary wartime pamphlet or report describing the defection of two cavalry regiments from the forces of the Kingdom of Westphalia to the anti-Napoleonic coalition during the German campaign of 1813.
The text focuses on the dramatic shift of allegiance by the two Westphalian hussar regiments commanded by Colonel von Hammerstein and Major von Pentz. In the night of 22–23 August 1813, during the broader collapse of Napoleonic control in Central Europe, these units are described as breaking from their assigned French-aligned command structure and joining the Allied forces opposing Napoleon. This event occurred during the wider War of Liberation phase of the War of the Sixth Coalition.
The pamphlet presents the defection as a decisive and symbolic moment, emphasizing loyalty shifts within German auxiliary forces that had previously served under Napoleonic satellite regimes. Such transitions were not uncommon in 1813, as military pressure increased following French setbacks in Russia (1812) and widespread unrest among German contingents serving under Westphalian administration.
The narrative likely highlights the coordination, secrecy, and timing of the move, framing it as a deliberate act of alignment with the “national” or “liberation” cause. It reflects the rapidly changing political and military landscape in which units raised under French influence began to reorient toward coalition forces, especially Prussia and its allies.
As a 1813 publication from Marburg, the work functions both as a report and as wartime propaganda, intended to document and legitimize the defection of troops from a Napoleonic client state. It is valuable today as a primary source illustrating the fragmentation of Westphalian military structures in the final year of its existence and the fluid loyalties of German units during the late Napoleonic Wars.
