Diarmaid MacCulloch in The Guardian:
Thomas Cromwell's ghost must be blessing Hilary Mantel for her two novels so far, and one more to come, restoring him to a life by turns engaging and intimidating. Equally, the theatre versions of Wolf Hall and Bring Up the Bodies have been triumphs, enriching Mantel's artistry with Ben Miles's extraordinary performance as Cromwell. Each play puts Miles on stage for nearly three hours, and he exhibits as much energy as the original Tudor statesman did in 10 years of public service to Henry VIII. It's a marvellous re-creation of an all-seeing polymath: he is witty, reflective, affectionate and calculatingly brutal, always visible to the audience, if not to his fellow players.
This ingenious dramatic device of Mantel's plays precisely makes Cromwell present even when he isn't saying anything, and that is an effective way of conveying the peculiar nature of his vast surviving set of papers, now split between the National Archives and the British Library, with a clutch of strays elsewhere. The surprise of those manuscripts is that Cromwell himself is hardly there; the thousands on thousands of documents are his in‑tray, so sifting through them is like listening to the noise of suppliant voices pouring into his ears while he himself sits, silent, as in his famous black-clad portrait by Holbein, contemplating the babble of 16th-century Europe, and grasping one of those letters, tightly.