Instruction:
What happened to Ned Stark's ancestral family greatsword, Ice?

Response:
After he was beheaded, Ned Stark's family sword was taken by Tywin Lannnister and reforged to make two longswords: Widow's Wail, which was gifted to his eldest grandson, Joffrey, and Oathkeeper, which was gifted to his son, Jaime.