Short answers, pulled from the story.
The First French Empire was proclaimed on the 18th of May 1804, when the French Senate granted Napoleon Bonaparte the title Emperor of the French. He was formally crowned on the 2nd of December 1804 at Notre-Dame de Paris, with Pope Pius VII presiding over the ceremony.
At its height in 1812, the First French Empire had 130 departments and a population of over 44 million people within France. Napoleon ruled over 90 million subjects across Europe and maintained military forces in Germany, Italy, Spain, and Poland.
The Napoleonic Code was a legal reform system introduced throughout the territories France controlled. It established legal equality, jury systems, the right to divorce, and abolished seigneurial dues and aristocratic privileges in all conquered territories except Poland.
The Empire's collapse began with the catastrophic 1812 invasion of Russia, which resulted in the near-total loss of Napoleon's army. Spain's sustained guerrilla resistance drained French forces, betrayals by key marshals and ministers undermined the regime from within, and by 1814 a coalition of European powers invaded from all sides. Paris capitulated on the 30th of March 1814.
Napoleon was exiled to the island of Elba after his abdication at Fontainebleau on the 11th of April 1814. He escaped less than a year later with a thousand men and four cannons, briefly restored the empire during the Hundred Days in 1815, but was defeated at the Battle of Waterloo and exiled to Saint Helena in the South Atlantic, where he died in 1821.
Napoleon came to power through a coup on the 9th of November 1799, organized with Director Emmanuel Joseph Sieyès, his brother Lucien Bonaparte, and Talleyrand. He then outmaneuvered Sieyès by drafting the Constitution of the Year VIII and securing the First Consulship. A national plebiscite in 1802 returned 3,653,600 votes in favor of making him Consul for life.