Se n Duffy 
Ireland in the Middle Ages [PDF ebook] 

This book surveys Irish history in the first half of this millennium, written in a style which will make it accessible to those new to the subject, incorporating the findings of recent research, and offering a reinterpretation of the evidence. Rather than having the English invasion as its starting point, as is previous practice, the volume places it as its centrepiece, and traces in detail the pre-invasion background. While acknowledging the importance of the English invasion as the single most formative development in Irish secular affairs, this book emphasises the importance of politics in native Ireland, which has sometimes in the past been neglected.