New ancient DNA analysis has shed light on how the black rat, blamed for spreading Black Death, dispersed across Europe – revealing that the rodent colonised the continent on two occasions in the Roman and Medieval periods. The study, led by the University of York along with the University of Oxford and the Max Planck Institutes for the Science of Human History (Jena) and Evolutionary Anthropology (Leipzig), is the first ancient genetic study of the species, also known as the ship rat.