Sad to say, but many books written by academics are dry and dull. This one by historian MacMullen is an exception. Not only does he present as lively a picture of the emperor Constantine 'the Great' as we're able to surmise, but he manages to convey something of the cultural atmosphere of Rome, East and West, during the fourth century--and he does this, punctuating his text with occasional flashes of humor. I imagine he was a popular lecturer.
The biggest controversy surrounding Constantine concerns his 'conversion' to Christianity, then a minority movement. Here MacMullen does an admirable job in reconciling Constantine's behaviors with his beliefs, basically by downplaying the latter and emphasizing the practicalities of the former. Constantine was certainly not a Christian in any deep sense. Indeed he only submitted to baptism at his deathbed. As regards theology, he had little sense, his own 'Christian' god being barely distinguishable from the pagan 'monotheism' of Sol Invictus. As regards ethics, he was quite selective with little or no regard for the implied ethics of the gospels or the explicit ethics of the Sermon on the Mount or Beatitudes. One wonders--and here MacMullen makes no claim--if he ever read the gospels.
Highly recommended.