An equestrian burial from the 10th century with an exceptionally elaborate horse harness was discovered at Fregerslev near Skanderborg in eastern Jutland, Denmark in 2012. This formed the starting point for the Fregerslev Research Project initiated by Museum Skanderborg in 2017. Two years later, the museum held a conference to present the preliminary results of the project. A group of researchers from neighbouring countries were invited to provide a wider international context for a discussion of the social, political, cultural and religious background of the Fregerslev burial. With 21 articles, Horse and Rider in the late Viking Age presents the outcome of the conference. Part I describes the excavation of the Fregerslev burial and its contents. The finds, particularly the harness fittings and the remains of a quiver of arrows, and the results of a wide range of scientific analyses demonstrate what a remarkable burial this once was. The excavation methods and documentation procedures, the sampling strategies, and the following conservation and preservation of the finds, give an idea of the many new approaches, which may be useful when dealing with a decomposed grave in the future. Part II and Part III present new research on 10th-century equestrian burials and their significance in contemporary society from a variety of countries across Central and Northern Europe.