SignificanceWhile our knowledge of modern plague reservoirs and their hosts is extensive, we have little to no knowledge about the origin of the Medieval plague pandemics or the routes of transmission involved in their spread. Prior genomic data provide a patchy low-resolution picture of the transmission dynamics involved during the Second Plague Pandemic, with only five distinct genomes. We have reevaluated all Medieval strains under the light of archaeological and historical evidence to carefully discuss the involvement of different transmission routes during the Second Plague Pandemic. Our interpretation showcases the importance of trade routes and human movements and further supports the identification of Yersinia pestis as the pathogenic agent of the so-called pestis secunda (1357–1366).

SignificanceLouse-borne relapsing fever was one of the major diseases affecting Western human populations, with its last major pandemic killing millions after World War I. Despite the major role fevers have played in epidemic events throughout history, molecular evidence for the presence of their etiological agent has been extremely scarce in historical samples worldwide. By comparing our medieval Borrelia recurrentis genome with modern representatives of the species, we offer an historical snapshot of genomic changes in an immune-evasion system and of reductive evolution in a specialized vector-borne human pathogen. This shotgun sequencing project highlights the potential for ancient DNA research to uncover pathogens which are undetectable to osteological analysis but are known to have played major roles in European health historically.

At least 36 graves are known from Avaldsnes headland and the immediately adjacent islets and islands. These include two monumental mounds, a raised stones monument, four stone packings, and 15 mounds or cairns that have been identified based on morphological traits across the headland; written sources account for one additional eradicated mound with a raised stone. Several of the monuments contained multiple burials. In addition, four stray finds likely representing graves have not been securely connected to known monuments. Most of these graves have not been the objective of professional excavations, although some documentation is preserved from the 19th-century excavation in Flaghaug. Nine of the graves of various forms were excavated or superficially examined professionally in the 20th century, in addition to the limited excavations of the remains of Flaghaug and Kjellerhaug grave mounds by Avaldsnes Royal Manor Project in 2011-12. The aim of the Flaghaug investigation was to obtain information on its construction and to assess the potential for recovery of artefacts from the remains. The details of the individual secondary burials in Flaghaug are published by Frans-Arne Stylegar and Håkon Reiersen in this volume. The aim of the investigation of Kjellerhaug was to reveal the construction details and stratigraphic relations of the mound as well as to recover datable material in order to obtain a more precise date for the monument. Although the excavations were limited in scope, they succeeded in providing datings of the monuments, along with insights into the landscape and the monuments' history. This chapter also provides an overview of all recorded graves and grave finds at Avaldsnes, which forms the basis for discussing the development of the ritual landscape at Avaldsnes and its relation to the contemporary settlement. The large number of grave monuments at Avaldsnes demonstrates the site's importance in terms of ritual activity and demarcation of social status in the Bronze and Iron Ages. The large grave mounds and the raised-stone monument held a special position, in part due to their clear visibility to people sailing through the strait.

Surveys and excavations carried out at Avaldsnes 1985-2012 are described in this chapter, the main focus being on the Avaldsnes Royal Manor Project 2011-12 excavations. In sum, the campaigns conducted surface surveys, metal detecting, soil coring, test trenching, open-area excavation, as well as geophysical surveys and scientific sampling. Following a brief account of the extent and results of the 1985-2006 campaigns, the methodology and extent of the ARM excavations are described. Also addressed are the challenges related to investigating a site with such complex history including continuous activity in central areas as found at Avaldsnes.

This chapter describes and discusses three identified and one possible prehistoric building at Avaldsnes, alongside an overview of the settlement's organisational layout during various periods of prehistory. The buildings vary in age, size, and function; all these aspects are discussed. Each building is treated in its own section, with an initial description that clarifies the building's essential construction elements, followed by discussion of its possible functions. The poor preservation of the buildings, particularly in Area 1, complicates the interpretation, as aspects of their construction and functions remain unknown. The archaeological features are the main material for the discussion, supplemented by macrofossil and micromorphology analyses, osteology, soil chemistry, and artefacts. The excavations, coupled with previous surveys at Avaldsnes, indicate a settlement that existed over a long period of time, during which the site's organisation became increasingly fixed and the site's various functions increasingly localised in specific areas.The excavation plan for the Avaldsnes Royal Manor Project was conducted with the stated aim of examining those elements that might elucidate the settlement's social status, as well as identifying possible reorganisations of the settlement that could imply changes in social status. The fragmentary building remains uncovered were difficult to interpret, but a tentative assessment from the stated perspective is still plausible.Prior to the excavations of the current project, no complete prehistoric buildings were known at the Avaldsnes headland, although postholes and other construction remains had been identified in Areas 1-6 and on the Kongshaug ridge in the course of surveys carried out by the Museum of Archaeology in Stavanger in the period 1992-2006 (Bauer and Østmo, Ch. 5:68-70). As previous investigations were limited to surveying, most of construction remains were documented only superficially, and only a small selection were radiocarbon dated or dated by stratigraphic relations. As such, the 2011-12 excavations provided a wealth of new information in terms of the chronology, spatial distribution, and function of the features excavated. Some of the areas surveyed earlier were not included in the excavation areas of the Avaldsnes Royal Manor Project, leaving unknown the character of these settlement remains, particularly the features at Kongshaug. This elevated ridge running northsouth for approximately 200 meters near the western border of Area 2 was dominated by grave monuments of various forms and dates (Østmo and Bauer, Ch. 12:243-5), most prominently a large stone packing in the southern end containing at least two graves. This grave monument was built over a group of postholes and cooking pits. The grave monument is believed to date from late Site Period (SP) II or early SP III, while the settlement traces must therefore predate this (Hafsaas 2005:12-17; 2006:22-3). It is unknown whether these postholes were components of dwellings or merely fences or other mi...