By 1806, France stood as the undisputed hegemon of Europe, forcing its rivals into a state of fearful acquiescence while its allies benefited from its protection. The Sultanate of Madjrit, stretched thin by conflicts in India and Egypt, accepted a French offer to garrison the Iberian Peninsula, effectively outsourcing its domestic security to the Republic. This arrangement unraveled in March 1806 in the Catalan town of Rus, where the heavy-handed collection of the Jizya tax by the Sultan’s officials sparked a riot. French troops, sympathizing with the locals' claims of oppression, stood by as the townspeople lynched the tax collectors. This inaction emboldened the populace, leading to a widespread rebellion known as the "Blues," a coalition of Catholics, Jews, and Muslims united against the Sultan's fiscal tyranny.

The Sultan, Abdul Al-Madini, then visiting Paris, viewed the uprising with aristocratic indifference, alienating his court back in Madjrit. Seizing upon this negligence and the humiliation of French occupation, the Sultan's traditionalist brother, Abd al-Malik, staged a coup in July 1806. Determined to restore national dignity, the new Sultan Al-Malik sought to break the French alliance. He secretly negotiated with Britain, which agreed to pay off Madjrit’s crippling national debt in exchange for a partnership. On July 25, 1807, Madjrit formally declared war on France, transforming the Iberian rebellion into a complex civil war where French troops openly supported the Blue rebels against the Sultan's forces.

The conflict in Iberia escalated dramatically with the arrival of a British army under General Lance Wayne in September 1807. Seeking to break the stalemate along the Nahr Ibruh River, Wayne orchestrated a daring naval landing at the French-held port of Bilbaw, threatening the French rear. This maneuver forced the French commander, General Lanjuinais, to divide his forces. At the subsequent Battle of Murjiyya on November 3rd, a surprise flank attack by British cavalry shattered the French lines. The defeat effectively destroyed Lanjuinais' corps and forced the French and their rebel allies to retreat into the mountains, handing the coalition a significant victory in the peninsula.

Meanwhile, in Central Europe, Austria worked tirelessly to forge a new alliance to challenge French dominance. While Russia refused to join due to its exhaustion and desire to maintain relations with Eastern Rome, Prussia was finally enticed into the war by promises of territory in the Rhineland and British subsidies. In September 1807, the Third Coalition—comprising Austria, Prussia, Britain, and Madjrit—was officially formed. Facing this renewed threat, the French Republic turned once again to Gaspard Lefebvre. Having been acquitted of treason by a jury that recognized his service to the state, Gaspard raised the 65,000-strong "Army of the Republic." He marched east to confront the Austro-Prussian forces, engaging in a month-long game of cat and mouse across Germany before finally pinning the coalition army near the town of Woikowitz in October, setting the stage for the largest battle Europe had ever seen.