By the winter of 1648–9, demands for retributive justice on Charles I and his supporters had built to a crescendo. But regicide was generally regarded as an extremely bad idea, and the king's trial was contrived as a final bid for peaceful settlement, not a prelude to king-killing. In return for a place at the heart of a new constitutional order, Charles I was required to abdicate his negative voice by pleading to charges brought on the sole authority of the House of Commons. This was a high-risk strategy inspired and justified by the weakening of opposition to the trial in the House of Lords, the city of London and at Edinburgh, and by some of the encouraging signals emanating from deep within the royalist camp itself. However, in their anxiety to avoid having their ultimate sanction forced upon them, the commissioners of the high court of justice gave the king rather more opportunities to plead to the charges against him than was consistent with the maintenance of their own authority. Rather than persuading him to give in, they encouraged him to stand firm, with fatal consequences. Far from being a providential act of vengeance, or indeed the inexorable fate of a man predestined to martyrdom, the execution of Charles I was a highly adventitious occurrence – predictable, perhaps, yet contingent on a wide range of unpredictable circumstances.