January 30th is the feast day of Charles, King & Martyr for many within the Church of England, as well as some around the Anglican Communion, including the members of the Society of King Charles the Martyr. This is a particularly interesting and ambivalence-inspiring observance for Americans, given our own elevation of democracy to divine status. It is for this reason, of course, despite regular attempts, that Charles Stuart has never been on the official calendar of the Episcopal Church.
The long and short of it is that Charles I was a poor politician, and an ineffective ruler who is, by today’s standards, seen as despotic (though, of course, no more than many current petty dictators with whom we are happily allied!). All the same, he was a sight better than the Lord Protector, Oliver Cromwell (though the importance of Cromwell’s readmittance of the Jews to England shouldn’t be overlooked), and seems to have been a decent human being who was committed to his principles and his faith. Because of this, it did not take the people of England very long to look with fondness upon the days of Stuart rule, as opposed to the equally oppressive (and much more stodgy) rule of the puritans.
I think the best summary of this that I’ve read is in JRH Moorman’s A History of the Church in England:
On January 30, 1649, the king was beheaded on a scaffold outside the banqueting-house in Whitehall.
When the bleeding head was held up, the cry of horror from the crowd drowned the derisive shouts of the soldiers. During the trial and at the hour of death Charles had behaved with a quiet courage and dignity which had won many to his side, even among those who had been ready to take up arms against him seven years before. Royal despotism was a bad thing, but military despotism was worse. English people dislike the sight of blood; and the execution of a king sent a thrill of horror and detestation through the country which has never been forgotten. It has been described as ‘a crime against England even more than against Charles’. But not only did it outrage the deepest feelings of the country, it also alienated many who might have been Cromwell’s supporters, and thus made a restoration of monarchy and Church inevitable in due course. The regicides little realized that in cutting off Charles’s head they were cutting their own throats.
From 1662 to 1859 the execution of King Charles was commemorated in the calendar of the Prayer Book and special services were held each year on January 30. Charles thus came as near to canonization as it is possible to be in the Church of England. he stood as a symbol of the patient sufferer who lays down his life for his creed and for his Church. He was certainly a good man and devout. He had great courage and firm convictions. In his own way he was convinced that he was doing what was right. His father had taught him that the Divine Right of Kings was part of the will of God, and he had upheld this doctrine even unto death. Such devotion to duty, such readiness to die rather than surrender his belief, is worthy of honour. But his faith in Divine Right made him exasperating to others, especially his enemies. His duplicity and irresponsibility, to which, in his own mind, he was perfectly entitled, to others appeared as sheer dishonesty. To Cromwell there could be no peace for England so long as Charles Stuart was there to disturb it; hence the desperate remedy of a royal execution. So Charles died; but with his death the fate of Puritanism was sealed and the Church’s future ensured. (Moorman, p. 240-241)