Benjamin was the son of Jacob and Rachel and father of the tribe of Benjamin, one of the twelve tribes of Israel. Originally named Ben-oni, or "son of my affliction" by his mother as she lay dying in labor, his name was later changed to Benjamin, meaning "son of my right hand" (Genesis 48:14). Next to Joseph, he was his favorite son. Benjamin the twelfth son of Jacob and born after Joseph was sold into slavery. After the family was invited to Egypt, Joseph sabatoged Benjamin's sack by putting a silver cup in it and accusing the brothers of stealing. Joseph thought Benjamin would remain in Egypt but Judah offered to take his place, saying that his father would be devastated if Benjamin did not return. Jacob later blesses Benjamin while on his deathbed, calling Benjamin "a vicious wolf, devouring the prey in the morning, and dividing the spoil at night" (Genesis 49:27).
Sources: Bridger, David. Ed. The New Jewish Encyclopedia, NY: Behrman House, 1976; Navigating the Bible II