I really appreciated the historical aspects. Medieval England, with a modern day conspiracy. As young adult fiction, the historical elements aren't overly complex, so the reader don't need be weary of such elements. In truth the author does an excellent job simplifying a very complex history and still remains very close to the facts and actual myths. I usually go and read more about the history alluded to due to personal interest. For example the English king spoken of in the book is Richard I who reigned from 1189-1199. His title lion heart comes from his crusades against the Kurdish Muslims occupying the Holy lands (including Jerusalem) and his later battles in France. Richard is described as a somewhat unlikeable character in the book, which is understandable considering he was always more interested in war than ruling and that the English did pay dearly for his release after he was captured by the Duke of Austria. His release cost a third of every English man's wages for an entire year. John Lackland did then succeed Richard and ruled from 1199-1216. John also did eventually sign the Magna Carta on 15 June 1215 under the threat of civil war. This is a royal charter of rights that was adjusted by various Kings and according to various times, but essentially served to protect individual english freedoms and served as foundation to the contemporary power under which a person has the right to be heard by a court of law and not be imprisoned unjustly. Back to the book. SPOILERS: This book has several converging storylines and not everything was as captivating. I like Robin Hood and see why and how this part supports the plot, but didn't particularly like that Robin Hood was depicted as a robot from the future taking orders. Then, the ex-templar monk and the cryptologist from the future were quite interesting characters, so I'd actually have liked to know more about them. And, I like that the Holy grail hints at something mysterious with terrible consequences for a doomed future, but its frustrating that the whole plot to decode the message of the grail is still a mystery. Sometimes it felt like there were too many separate storylines, but overall the book was likeable.