This is an officially licensed Game of Thrones replica made by Valeryian Steel. This is "Oathkeeper", one of two swords made from Ice, the ancestral sword of House Stark. While initially given to Jaime Lannister by Lord Tywin with the intention of making it an heirloom of their house, Jaime instead gave it to Brienne of Tarth for the task of rescuing Sansa Stark.
Oathkeeper is 41 1/2" overall with a 32" stainless blade. The hilt is bronze plated with jewels.
Each limited production Valerian Steel (tm) replica is individually serialized with a certificate of authenticity and includes a wall-mount wooden display plaque with a silkscreened House of Tarth sigil.