|The title of this article is conjecture based on information revealed in the A Song of Ice and Fire novels or related material and may be subject to change.
When Dalton Greyjoy and his Ironborn attacked the Westerlands, Johanna was able to bar the gates of Casterly Rock, but the Ironborn were still able to burn the Lannister fleet and sack Lannisport. After Dalton was killed, Johanna was able to attack the Iron Islands, where Lannister troops put several of the locals to the sword and burned the villages and longships.
In the books
During the retributive attack on the Iron Islands, Lady Johanna allied with the lord admiral of the Reach, Ser Leo Costayne. After one of Dalton Greyjoy's salt sons was taken to Casterly Rock as a captive, Johanna had him gelded and made him her son's fool. Following the end of the civil war, Johanna restored House Lannister to its former glory and lent gold to King's Landing to help rebuild the severe damage caused by the war.