Final answer:
The character referred to by the titles Ring-giver, protector of the Danes, The Shield of his people, and Halfdane's son is Hrothgar from the epic poem Beowulf.
Step-by-step explanation:
Ring-giver, protector of the Danes, the shield of his people, and Halfdane's son are all references to the character Hrothgar in the epic poem Beowulf. These appellations are characteristic of the poetic and heroic language used throughout the poem to describe the esteemed characters, particularly those of high status such as king or noble. Hrothgar is the king of the Danes and the son of Halfdane, and as such, he is portrayed as the protector and benefactor to his people, which is reflected in the ceremonial titles he is given.