|Although this article is based on canonical information, the actual name of this subject is pure conjecture.
The Retaking of the Iron Islands was a successful attempt by the Ironborn forces loyal to Queen Yara Greyjoy to retake the Iron Islands from King Euron Greyjoy, who was in King's Landing to help Queen Cersei Lannister defend King's Landing from Queen Daenerys Targaryen.
Following her rescue at her brother's hands, Yara decided to use the few ships and men still at her command to take the Iron Islands back from her treacherous uncle. Meanwhile, Theon took a small portion of this force north to fight and ultimately die for the Living at the Battle of Ice and Fire.
According to the reports of Varys, the reconquest was successful. Considering the bulk of Euron's fleet was occupied serving Cersei on the other side of the continent, Yara's men likely encountered little resistance.