When I saw this title, I believed I was going to read a historical novel about Cyrus de Great, founder of the Persian Empire who would be telling his own story to a scribe or somehow writting his memoirs. This belief was reinforced by the book's subtitle (the story of the real Prince of Persia). This is NOT what I got. Instead, the book is a mixture of some historical facts, quite a heavy dose of fiction and fantasy and a tale told as if it was a legend. It made me think of something out of Sheherazade and the tales of the one thousand and one nights. At the outset, that rather put me of. Then there was the book's tone and the story telling. Not only did it not "sound and feel" real - quite the opposite in fact - but I also got the impression that this was for teen-agers. The latter, of course, is not a criticism, it's just not what I was expecting, given the way "the goods" had been advertised.
Having said that, the book is worth reading as long as you do not mind you novels taken liberties with what little historical records we have on Cyrus. First of all, Smerdis was NOT the son of Roshan. He was the full brother of Cambyse, with an inscription from Darius the First explicitly mentioning that they had the same father and mother. Second, the so-called tolerance exhibited by Cyrus is true, but only to a point. It was more politically motivated and self-interested than really driven by any "humanitarian" considerations. As for Cyrus' supposed drive against slavery, this would had quickly contradicted his supposed tolerance policy with regards to the vanquished kingdoms who heavily relied on slave labour (Babylon, in particular). Neither were any of his campaigns the kind of "walk-overs" that they are made to be in the book.
In fact, each of them was hard fought. It took at least three years of war for Cyrus to conquer Media. If Harpagus did rally Cyrus against Astyages, this was not enough to tip the scales straight away and Cyrus initially suffered a couple of defeats. Moreover, Astyages lead his own troops on at least one occasion and, since he was supported by at least some of the Medes, he probably was not the "arch-villain" that he is portrayed to be, neither was he killed when Cyrus and Harpagus entered Ecbatana. The same can be said of the two other great conquest, the kingdoms and their monarchs, whose name has been deliberatly blackened.
Croesus was no fool and did not surrender easily. A first battle that took place near the Halus was a bloody draw. However, Cyrus caught his ennemy by surprise by continuing to campaign after the Lydians had withdrawn for winter. This is how Cyrus won his second battle against the Lydians and close to Sardis: Croesus was forced to fight with whatever troops he had been able to gather. So, while the story of the camels frightening the Lydian cavalry is a good one, strategic surprise and the fast moving Persian army are probably much more likely explanations, although, of course, less romantic and colourful.
As for Babylone, it seems that the hostilities started well before 539 BC - at the vey least one year before and possibly even earlier as the eastern province of Babylonia was first conquered and its governor rallied Cyrus (and would latter be Cyrus' Governor of Babylone). Then a pitched battle was won by the Persian at Opis. Although not mentioned at all in the book, it seems to have been hard fought. Only then did the siege of the city start. Diverting the waters of the city did lead to its surrender. So, the city was not stormed. There was no lengthy siege but the Babylonians did not give up without a fight.
As for the wars against the "Massagetae", these were in fact part of the almost constant (or at least endemic) warfare that the Persians (and the Medes, the Assyrians, Babylonians and many others) had to wage against the Skythian nomadic tribes that were roaming between Central Asia and the Danube. Most historians accept that Cyrus had to wage war against them at least three times during his reign. Once possibly after conquering Media. The second time, and for several years, after conquering Lydia, and the third time in 530 BC leading to his death. THis does not mean that there was constant war on the Persian Empire's north-west borders, although they probably was almost constant raids and incursions. Some of these must have been wide-scale enough so that the local governor was unable to tackle them on his own, forcing the King of Kings to take matters in hand.
So, a rather good read, despite being non historical and more of a story telling bordering on the fantasy-side. Not bad, in fact, but not at all what I had expected and was looking forward to read...