Deuteronomy 33: 12 About Benjamin he said: “Let the beloved of the Lord rest secure in him, for he shields him all day long, and the one the Lord loves rests between his shoulders.”
Genesis 49:27 “Benjamin is a ravenous wolf; in the morning he devours the prey,
in the evening he divides the plunder.” (NIV)
The prophecy by Moses in Deuteronomy is started with Jonathan (King Saul’s son) and David in 1 Samuel 18. It continues in 1 Kings 12 when a rather arrogant Rehoboam is used to split the Kingdom; ten tribes follow Jeroboam and only Judah and Benjamin stay true to the royal line of David. (Jerusalem was in the land allotted to Benjamin.)
The prediction of Jacob in Genesis 49 paints an interesting picture of his youngest son. A wolf is relentless and calculating when it pursues what it wants and violent in its attacks but it also sets an example of a supportive family. I think it is safe to assume that when Joseph was “no more” that Benjamin became his favored son. This is reflected by his unwillingness to let him go to Egypt even though the whole clan could have died of starvation.
Since Rachel died in childbirth who raised Benjamin? Bilhah should have been the likely choice since she was Rachel’s slave but she slept with Reuben and I cannot image Jacob trusting her much. So the other choice would have been faithful Leah.
The story in Judges 19,20,21 about Benjamin defending some of their own even though they had clearly crossed several lines of moral behavior sets the stage for Saul and his kingship. (See Why Hide a Grandson There)