Second paragraph of third chapter:

About 50 years later, however, the first William de Courcy of Stogursey granted all of his lands to his own first son, named William after him, undoubtedly expecting him to make some provision for his younger brothers, but keeping the lordship itself in one piece and firmly under Courcy family control. Although the father might have been tempted to provide for all his sons by dividing up his lands, when he passed everything on to his eldest son he ensured that the integrity and strength of the lordship would be maintained. Dividing it up into three parts, even unequal parts, would have substantially reduced the financial and military strength of the lordship and consequently lowered the status of the second William de Courcy amongst his fellow aristocrats. Having established himself in England, the first William de Courcy was clearly determined that his family should maintain its status within the highly-competitive Anglo-Norman aristocracy and for that the new lord, his eldest son, needed as large a lordship as possible.

A very short book about the Norman knight who conquered "Ulster", or rather most of what is now County Down and County Antrim, in the late twelfth century. It's very good on the details of the de Courcy lineage and family holdings in France and England, which goes some way to explaining the drive to expand the family domains. The military details of the crucial capture of Downpatrick in 1177 are examined at length, and lots of other bits and pieces are thrown in, particularly on the record of de Courcy's military patronage and shifting of the centre of gravity of the Ulster lordship to Carrickfergus from Downpatrick.

But lots is left out as well. There is nothing about the attempted mediation role of Cardinal Vivian in the Downpatrick attack, though it's a major part of the narrative in contemporary chronicles. The dramatic story of de Courcy being captured while attending church in 1204 is skipped over. We don't get anything about how the new Norman rulers were able to displace the former Irish chieftains so quickly and so comprehensively. I also think there is a story to be told about de Courcy's wife, Affreca, the daughter of the King of the Isle of Man, and the fact that almost all of the Anglo-Norman fortifications of the Lordship of Ulster are so close to the sea.

It's also frustrating that no sources are given (though at least there are some good maps). Flanders has done some delving into the surviving charters and other records, but unfortunately hasn't shown his work. I learned a couple of things from this, but basically T.E. MacNeil's Anglo-Norman Ulster has far more information and is just as digestible. Still, if you want to, you can get it here.