Haftvad and Shahvi on the Gibbets

From D6.16, Ardeshir Slays Haftvad. It illustrates D6.16.10–16:

D6.16.10
The wind now turned against proud Haftvad’s side;Soon he was seized, his boast and power denied.
D6.16.11
His eldest son, Shahvi, was also bound;The battle-chief was captured on the ground.
D6.16.12
Ardeshir left the rampart and came down;Shahrgeer came on foot before the crown.
D6.16.13
They brought a steed with golden trappings bright,And Shah Ardeshir mounted in their sight.
D6.16.14
He ordered two tall gibbets on the strand,To rise beside the sea at his command.
D6.16.15
He hung both living foes upon that height,And woke his enemies to fear their plight.
D6.16.16
From out the army’s center Shahrgeer sped,And rained his arrows till the two were dead.