Raid on Torrhen's Square

The Raid on Torrhen's Square was a battle during the War of the Five Kings. It was part of a ploy by Theon Greyjoy - who had abandoned House Stark and aligned himself with his father Balon Greyjoy, the self-fashioned King of the Iron Islands - to seize Winterfell and gain the respect of his father and fellow ironborn.

After news of an unidentified party attacking Torrhen's Square reached Winterfell, Prince Bran Stark sent Rodrik Cassel to defend the Stark bannermen of House Tallhart.

With Winterfell undefended, Theon led his crew to the castle to take it.

In the books
In the books, the attack on Torrhen's Square is led personally by Dagmer Cleftjaw. He is driven away by Ser Rodrik Cassel and men from House Cerwyn back to the Stony Shore.