Short answers, pulled from the story.
The War of the Fifth Coalition began when Austria invaded Bavaria on the 10th of April 1809 without a formal declaration of war. Emperor Francis I launched this attack because Russia and Prussia remained neutral despite Austrian hopes for their support following the Treaty of Tilsit.
Archduke Charles commanded the main Austrian army throughout the conflict after implementing major reforms since 1805. Senior officers were appointed based on aristocratic backgrounds rather than ability resulting in an average age of 63 years among generals.
The Battle of Aspern-Essling started at 2:30 pm on the 21st of May 1809 and concluded by nightfall on the 22nd of May. This engagement resulted in the first major defeat of Napoleon's military career and the death of Marshal Lannes from a cannonball wound.
Napoleon defeated Archduke Charles at the Battle of Wagram on the 5th and the 6th of July 1809 forcing the Austrians to withdraw. The French suffered around 32,000 casualties while Austrian losses stood at approximately 35,000 men.
Austria lost over three million subjects which represented about 20% of its total empire population after signing the Treaty of Schönbrunn. The treaty also required Emperor Francis to pay an indemnity equivalent to almost 85 million francs and ceded territories including Carinthia Carniola and Adriatic ports to France.