From A Wiki of Ice and Fire
|Siege of Storm's End|
|Conflict || War of the Five Kings|
|Date || 300AC|
|Place || Storm's End|
|Result || Unresolved|
The Siege of Storm's End refers to the action taken by forces loyal to King Tommen Baratheon to take Storm's End, one of the lost strongholds belonging to the rival King Stannis Baratheon.
Most of Stannis's bannermen kneel to King Joffrey Baratheon after Stannis's defeat in the Battle of the Blackwater. Aside from garrisons at Storm's End and Dragonstone, the remaining lords loyal to Stannis travel with him to defend the Wall and Castle Black from wildlings. King Joffrey dies at his wedding, and he is succeeded by his younger brother, Tommen Baratheon.
To remove Lord Mace Tyrell from the capital, Cersei Lannister commands him to lay siege to the castle of Storm's End, which remains loyal to Stannis Baratheon and is held by Ser Gilbert Farring. When Tyrell arrives, he sets up two dozen mangonels, achieving little against the stout castle walls. Shortly after this, Lord Tyrell hears that his daughter Margaery has been imprisoned at the Great Sept of Baelor by the High Sparrow. Leaving a token force under Lord Mathis Rowan, he marches on King's Landing and orders Lord Randyll Tarly to return from Maidenpool and join him there.
Mathis Rowan continues his siege; the Golden Company is also said to be on its way for their own attack.
References and Notes