Hirluin's early history was not known only that he was a person of some importance in the Pinnath Gelin (Green Hills) area of Gondor. It was possibly that he was Lord of that area. He was the leader of three-hundred gallant green-clad and well-armed men raised for the relief of Gondor in the Pelennor Fields.
He came from Lebennin with three hundred of his men, who carried banners of yellow stars. Tall and proud, he was to the sight of his men, and he wore a helm of great steel matched only by that worn by the Fountain Guard. Hirluin slew many orcs during the siege but he came to his doom when he was overwhelmed by the orc horde at the breaking of the door. Hirluin was buried before the gate at which he fell alongside Forlong at the Battle of the Pelennor Fields. Afterwards, the memory of his death as with others was lamented in the Mounds of Mundburg.
Hirluin was a Sindarin word for 'lord-blue' or 'blue-lord'.
- The Lord of the Rings: Minas Tirith pg. 771
- The Lord of the Rings: The Battle of the Pelennor Fields pgs. 846 & 849
- The Complete Guide to Middle-earth
- The Atlas of Middle-earth pg. 88