The History and Range Expansion of Peregrine Falcons in the Thule Area, Northwest Greenland covers the discovery and history of the most northern breeding population of Peregrine Falcons in the world, near Thule Air Base in northwest Greenland (75.9–77.6° N). Although the region was explored by scientific expeditions as early as 1818, Peregrines were not documented in the area until the 1930s. By the early 1990s the population had become well established, with a warming climate enabling Peregrines from further south to expand their breeding range northward. Here Burnham and his co-authors present their comprehensive findings on the biology and ecology of this population based on thirteen years of research from 1993 to 2005. Kurt K. Burnham has worked throughout Greenland studying Peregrine Falcons and Gyrfalcons for the past 22 years. Highlights of his research include documenting Gyrfalcons spending extensive periods of time at sea during winter months and the use of some Gyrfalcon nests for over 2,500 years. Kurt is currently the President and CEO of the High Arctic Institute. William A. Burnham was President of The Peregrine Fund, an international conservation and research organization focused on rare and endangered birds of prey, from 1986 until his death in 2006. He authored more than 90 scientific papers and in 1993 started the research presented here in the Thule area, northwest Greenland. Ian Newton is a British ornithologist who has worked on many different aspects of avian ecology. He has published more than 300 papers in the scientific literature, and written a number of books on various aspects of bird ecology, biogeography and migration. He is perhaps best known for his long-term studies of birds of prey, especially the European Sparrowhawk. Jeff A. Johnson is an Assistant Professor at University of North Texas and interested in conservation, population genetics, phylogeography and evolution. Andrew G. Gosler is a University Research Lecturer, Human Sciences Lecturer in Biological Conservation and head of the Institute of Human Sciences at Oxford University. Much of his past research has broadly focused on the local adaptation of tits in Wytham Woods, to include the functional ecology of eggshell pigmentation and winter fattening in small passerines.