Almost everyone knows about Christianity in Gaul during the first two or three centuries CE is connected with the Christian communities in Vienne and Lyons in the latter decades of the second century. The precious excerpts, some rather lengthy, of letters written by Christians in Gaul, which Eusebius preserves, and the writings of Irenaeus of Lyons, arguably the important Christian figure of the second century, offer a vivid picture of the remarkable vitality and diversity of these communities. The areas of Gaul in which Christianity appears in the second century CE are marked by the confluence of several forces and peoples. The most important event for the identity of Gaul during the author's period, and for subsequent European history, was the Gallic wars, the eight successive campaigns against Gaul and Britain lead by Julius Caesar between 58 and 50 BCE. The theological seeds that Irenaeus brought with him from Asia clearly flourished into a profound legacy for Christianity in Gaul.