What is "sonatorrek"

Sonatorrek ("the irreparable loss of sons") is a skaldic poem in 25 stanzas by Egill Skallagrímsson (ca. 910–990). The work laments the death of two of the poet's sons, Gunnar, who died of a fever, and Böðvarr, who drowned during a storm. It is preserved in a few manuscripts of Egils saga Skalla-Grímssonar, ch. 78. According to the saga, after Egill placed Böðvarr in the family burial mound, he locked himself in his bed-chamber, determined to starve himself to death. Egill’s daughter Thorgerd diverted him from this plan in part by convincing him to compose a memorial poem for Böðvarr, to be carved on a rune-staff.