David was, originally, leader of the Tribe of Judah who became the second king of the united Kingdom of Israel, according to the Hebrew Bible and Old Testament.
King David Playing the Harp (1622) by Gerard van Honthorst
King David in Prayer, by Pieter de Grebber (c. 1640)
Samuel anoints David, Dura-Europos synagogue, now in Syria, 3rd century AD.
David and Goliath (1888), colour lithograph by German artist Osmar Schindler
Goliath was a Philistine warrior of giant stature who plays a pivotal role within the Biblical story's legendary account of King David in the Book of Samuel. According to 1 Samuel, Goliath challenges
David
…young shepherd and harpist whose heart is devoted to Yahweh, the one true God. He gains fame and becomes a hero by killing the giant Philistine warrior Goliath. He becomes a favorite of Saul, the first king of Israel, but is forced to go into hiding when Saul suspects David of plotting to take his throne. After…
David hoists the severed head of Goliath as illustrated by Gustave Doré (1866)
Head of Goliath (V&A, Casts room)
David with the Head of Goliath, c. 1635, by Andrea Vaccaro