To be honest, I'm BAFFLED that this is so beloved by Christian homeschool families. One reviewer said it well when they noted, "It's like it was written by both a Christian and an atheist."
Of course, I must address that this book comes in many editions. It was originally written in 1923, and was subsequently updated and revised up until my edition from (I believe) 1994, printed in 2006. As far as I know, the Introduction is the only chapter original to the First Edition. I would KILL to have a first edition to which I could compare this one.
PROS: I adore Hillyer's idea of painting a history timeline (visualized as ascending steps-per-century) on the wall of a child's bedroom. I would have benefited so much from this as a kid, and will certainly be using this idea for my own kids.
I love how he described the Greek and Roman gods as "fairytales." This maintains the supremacy of Christian truth without alienating children from this important realm of history & culture.
The overall tone of the book is quite charming and easy to follow. The encouragements for children to judge their own virtue or lack thereof in comparison to figures like Socrates and Nero is capital stuff. However, he designates the book as best for 9-year-olds, whereas I would read this to a much younger child, probably 6 or 7.
CONS: This book is not a Christian book. I would say it is "pro-Christian," in that it supports Christian culture and values (for the most part). It tells a secular beginning of the universe and mankind. I was on board with the narrative throughout antiquity, but once it got to Jesus, it started to fall apart. When speaking about Jesus, it did not mention that Christians believe he is God, or that He resurrected after He was killed. It has nothing negative to say about Muhammad or Islam.
Its characterization of the medieval era in Europe as dark and ignorant is egregious and misleading. For example, it compared King Alfred's time-telling candle unfavorably to the "striking clock" of Harun Al-Rashid (which implies the sophisticated mechanisms of modern striking clocks, but this was really just a water clock), as if water clocks had not been in use from Greek antiquity, and as if candle clocks were not used by the Chinese and Arabs for centuries after Harun Al-Rashid.
As it heads into the 12th century, it becomes increasingly obvious that its method of simplification for a young audience is too simple to accurately portray historical events, and then it tries to apply improper Christian ethics to those oversimplifications. For example, the first crusade occurred when Christians attacked, unprovoked, all the Muslims in Jerusalem, eVeN tHoUgH the Bible says "He who lives by the sword shall die by the sword." Holy pseudohistory, Batman!
At the end of the book, it engages in some heavy war-alarmism AND war-utopianism. On the one hand, wars might get so bad that the entire world will be destroyed by bombs! On the other hand, someone might invent something that eliminates war forever! It also seems to posit that, despite admitting beforehand the United Nations cannot prevent war, the United Nations is still key in preventing war. There were several such contradictory statements throughout the book.
In conclusion, I would never read this to my kids or any kids in my care. But I would preserve its charming, whimsical skeleton and write flesh for it of a higher quality. And that historical timeline wall IS happening. Maybe in my own room.