There are seven patriarchs; Adam, Noah, Shem, Abraham, Isaac, Jacob, and Joseph. The word patriarch refers to the heads of prominent families of the Israelite tribes that appear in Genesis. The two focused on here are Abraham and David though David's title as patriarch is one more of honor rather than in actuality (Acts 2:29).
Here is King David seated upon his thrown. Over his head like the stars of the sky are depicted eleven of the twelve tribes of Israel. At bottom right is the symbol of the tribe from which he comes. "The lion of Judah". The six pointed star next to him, the star of David, represents the Kingdom of Israel. Notice that David holds are harp as he was a writer of songs. About half of the psalms in Scripture are attributed to him. To his immediate left is a young David playing for then King Saul. Below that is the head of Goliath. Just above the head is David's sling with the smooth, round rock in it. There is another rock embedded in the head of Goliath who was beheaded by David with his own sword and thus you see the river of blood flowing below.