Who send the plague to greek camp at beginning of iliad because chryses daughther was not returned?

The plague that struck the Greek camp at the beginning of the Iliad was sent by Apollo, the god of plague, disease, and archery.

Here's why:

* Chryses, a priest of Apollo, had offered a ransom for the return of his daughter, Chryseis, who had been taken captive by Agamemnon.

* Agamemnon, the Greek commander, refused the ransom and insulted Chryses.

* Apollo, angered by the insult to his priest and the disrespect shown to his daughter, sent the plague to punish the Greeks.

This plague caused widespread suffering and death among the Greek soldiers, forcing Agamemnon to reconsider his actions and return Chryseis to her father.