Short answers, pulled from the story.
Finckenstein Palace was built by Prussian Field Marshal Albrecht Konrad Reinhold Finck von Finckenstein and designed by architect John von Collas. Construction took place from 1716 to 1720 on land that was then part of West Prussia.
Napoleon used Finckenstein Palace as his residence from April through June of 1807 during the War of the Fourth Coalition. While there, he oversaw the signing of the Treaty of Finckenstein between France and Persia, and he lived at the palace with his Polish mistress Maria Walewska.
When Napoleon first saw Finckenstein Palace, he said "Enfin un chateau," which translates to "Finally, a castle."
The Treaty of Finckenstein was an agreement between France and Persia, signed at Finckenstein Palace in 1807. It was negotiated during Napoleon's stay at the palace.
Red Army soldiers set Finckenstein Palace on fire on the 22nd of January, 1945, during their conquest of Prussia in World War II. The palace has remained a ruin since then.
The Hollywood film Conquest depicted the events at Finckenstein Palace, with Greta Garbo and Charles Boyer in the lead roles. Despite the subject matter, the film was actually shot in Monterey, California.