Why is Bhai Dooj celebrated?

Bhai Dooj celebrates the brother-sister bond. According to beliefs, Yamraj visited his sister Yamuna, who welcomed him with tilak, which pleased the God of Death, who offered her a boon. She asked him to bless brothers with long life if their sisters applied tilak to them on this day. Another legend involves Subhadra welcoming Lord Krishna after he defeated Narakasura.