In the spring of 1815, Napoleon returned to Paris and reorganized the French army. The monarchs of Europe quickly assembled the Seventh Coalition, aiming to defeat Napoleon once and for all. Napoleon planned to strike swiftly, intending to crush the Anglo-Prussian forces first. However, Marshal Ney's delays and the misjudgment of the D'Erlon corps caused the French army to miss crucial opportunities. Additionally, an unexpected rainstorm provided the British forces with a much-needed respite. On June 18, the Battle of Waterloo erupted, with Napoleon personally leading the Imperial Guard into battle. However, British reinforcements arrived just in time to turn the tide completely. Ultimately, Napoleon announced his abdication and began his life in exile.