On the positive side, this is not just a narrative about a country’s internal and external power struggles. Chesterton’s history doesn’t, like too many others, equal the achievements of the ruling elite with national achievements. He cares as much, possibly more, what consequences such and such event or development meant for every Tom, Dick and Harry, as what it meant for any Edward, Henry and George.
On the negative side, his approach to facts is often, well, fanciful. One can smile condescendingly at his calling Robert the Bruce “a mere adventurer” and Edward I “the most just” type of mediæval monarch. However, his description of the High Middle Ages as the good old times when the nation headed under the spiritual leadership of the Catholic Church towards a utopian society (until aristocrats became more powerful than priests) brings us from a historical narrative to the realm of fairy tales. His perception of mediæval guilds as predecessors of socialist trade unions rather than capitalist cartels is dubious to say the least; and so on and so on.
That said, my primary reason for reading the book was getting some outline knowledge of English history, having been embarrasingly ignorant of large swathes of it. (For instance, I had known about William of Normandy, but not about Stephen of Blois; about the third Richard and Bosworth Field, but not about the second and the Peasants’ Revolt.) All things considered, that goal has been achieved.