Short answers, pulled from the story.
The House of Hohenzollern took control of the Margraviate of Brandenburg in 1518. This event marked the beginning of a long political journey that eventually created the Kingdom of Prussia.
Frederick III crowned himself King in Prussia on the 18th of January 1701. He secured permission from Emperor Leopold I in November 1700 to elevate his title before establishing the Kingdom of Prussia.
Prussia annexed most of Royal Prussia including Warmia during the First Partition of Poland in 1772. The newly acquired territory organized into West Prussia province with Marienwerder serving as capital while adjustments transferred Warmia districts to East Prussia.
Treaties signed at Tilsit in 1807 stripped Prussia of about half its territory following defeat at the Battle of Jena-Auerstedt on the 14th of October 1806. The kingdom lost all territory west of the Elbe river and faced French occupation of remaining lands under Napoleon's Continental System.
Otto von Bismarck took office as Prussian ambassador to France on the 23rd of September 1862. King William I appointed him following a budget dispute with parliament which allowed Bismarck to implement military reforms without parliamentary approval from 1862 until 1866.
King William II announced his abdication on the 9th of November 1918 during the German Revolution 1918-1919. This event ended the monarchy because the imperial constitution tied both crowns together while the military lost support for fighting on behalf of the monarchy.