Short answers, pulled from the story.
The Treaties of Tilsit were signed in July 1807 following preliminary negotiations between Napoleon I of France and Alexander I of Russia on a raft in the Neman River at Tilsit. The treaties created the Kingdom of Westphalia and the Duchy of Warsaw, and stripped Prussia of roughly half its territory.
Tilsit was occupied by the Red Army on the 20th of January 1945 during the East Prussian offensive and annexed by the Soviet Union that year. The town was renamed Sovetsk in honor of Soviet rule, and its German population was expelled under the Potsdam Agreement.
Tilsit cheese originates from the town of Tilsit, now called Sovetsk, in what is today Kaliningrad Oblast, Russia. Modern Sovetsk has attempted to revive the cheese tradition under the name Sovetsky cheese, but the renamed product has not inherited the reputation of its predecessor.
Daniel Klein (1609-1666) was a Lutheran pastor active in Tilsit who authored Grammatica Litvanica, recognized as the first grammar book of the Lithuanian language. He was among the notable 17th-century preachers working in the town's multilingual religious community.
When the Russian Empire banned the Lithuanian language in Latin characters within its borders, Tilsit served as a printing center for Lithuanian books smuggled across the border by carriers called Knygnešiai. Several Lithuanian newspapers and magazines were published there, including Auszra, Varpas, and Ūkininkas.
Notable people born in Tilsit include Edgar Froese (1944-2015), founder of the electronic music group Tangerine Dream; John Kay (born 1944), lead singer of Steppenwolf; and Armin Mueller-Stahl (born 1930), a German actor who became an honorary citizen of Sovetsk on the 8th of December 2011. The poet Max von Schenkendorf (1783-1817) was also a native of the town.