Short answers, pulled from the story.
The Gulating was one of four ancient regional assemblies, called lagting, in medieval Norway. It met annually at Gulen on the west coast, north of Bergen, from approximately AD 900 to 1300, functioning as both a legislative body and a court. All free farmers within its jurisdiction, the Gulaþingslǫg, had the right to participate.
The Gulating held its assemblies at Gulen, a site on the west coast of Norway north of Bergen, in what is now Gulen Municipality in Vestland county. The site was established early in the 10th century.
The Older Gulating Law is the oldest surviving record of Norwegian law. It was possibly first written down during the reign of Olaf the Peaceful, who ruled from 1066 to 1093, though some provisions likely existed in oral tradition as far back as the 10th century. It was replaced by the Younger Gulating Law in 1267.
The most complete surviving manuscript of the Older Gulating Law is DonVar 137 4to, also known as Codex Rantzovianus. It dates to around 1260 and is held at the Danish Royal Library.
In 1274, King Magnus the Lawmender replaced the Younger Gulating Law with his 'Law of the Realm', a unified national code. That code incorporated 130 chapters directly from the Gulating Law. Magnus also joined the four lagting into a single jurisdiction and had the existing body of law put into writing during the late 13th century.
The Gulating served as the direct model for the legislative assemblies of Iceland (the Althing) and the Faroe Islands (the Løgting). Both regions were settled by people from western Norway who carried the Gulating's assembly structure with them.