“In a hole in the ground, there lived a Hobbit…”
Bag End, built in TA 2889 by Bungo Baggins (Bilbo’s father), was a dwelling in Hobbiton, at the end of Bagshot Row. Bilbo inherited Bag End from his parents, and lived there on his own for a time, until he adopted Frodo Baggins, who came to live there as well.
Bag End was slightly more luxurious than the other Hobbit holes, and was greatly desired among the other Hobbits – in particular, Bilbo’s cousins, the Sackville-Bagginses. It was rumoured to have been stuffed with treasures, which Bilbo had acquired from the Dwarves of Erebor. Thus, Bag End gained a reputation as being both magnificent and mysterious.
Following Bilbo’s return to Rivendell and Frodo’s escape from the Shire, Bag End went to the Sackville-Bagginses in 3018. They remained there until Lobelia’s imprisonment and Lotho’s death; Bag End later became Saruman’s headquarters, and after his death, it fell back into Frodo’s possession.
Two years later, when Frodo sailed over the Sea and into the Undying Lands, Bag End and everything else in Frodo’s estate went to Samwise Gamgee and his heirs.