House Jast is a noble house of the Westerlands.
Their banner is an inverted pall between three lion's heads, yellow on black.
House Jast was formed by the union of First Men and Andal nobles during the Andal invasion.
Lord Antario Jast joins the Lannister army mustered by Ser Stafford Lannister. After the Battle of Oxcross, he is reported as having died to Tyrion Lannister in King's Landing. His sons are also captured by the northern army.
Lord Jast was not killed at Oxcross, but made prisoner instead. He spends the rest of the War of the Five Kings prisoner at Pinkmaiden Castle.
Antario is freed at the end of the war. The wounds received and the time he had spent prisoner affect him greatly, leaving him a shadow of the man he had been. Lord Jast joins the group which escorts Lord Tywin Lannister's body from King's Landing back to Casterly Rock.
House Jast sits in (NAME) keep, located in the Westerlands. It is situated just east of Kayce, northwest of Casterly Rock.