He had set off to secure an ally against Louis, and he came back from his expedition with a crown on his head and a new nation at his back, united in its detestation of popery and of France.
He suffered death on the 10th of January on Tower Hill, asserting his innocence of any offence known to the law, repudiating the charge of "popery," and declaring that he had always lived in the Protestant Church of England.
It was he who proposed a remonstrance against the growth of popery and the marriage of Prince Charles to the infanta of Spain, and who led the Commons in the decisive step of entering on the journal of the House the famous petition of the 18th of December 1621, insisting on the freedom of parliamentary discussion, and the liberty of speech of every individual member.
After some haggling a document called the Solemn League and Covenant was drawn up. This was practically a treaty between England and Scotland for the preservation of the reformed religion in Scotland, the reformation of religion in England and Ireland "according to the word of God and the example of the best reformed churches," and the extirpation of popery and prelacy.
Shaftesbury had assiduously kept alive the anti-popery agitation, and Monmouth, as the champion of Protestantism, was received with every sign of popular delight.
The kirk was incensed by the growth of Episcopalianism and of Popery, the restoration of patronage, and the pressure to accept an oath abjuring James, which divided a church that was absolutely anti-Jacobite.
But Modernism soon broadened into a thoroughgoing revolt against the modes of thought and methods characteristic of the latterday Vatican; its motto is that Catholicism is the strength of popery, but popery the weakness of Catholicism.
By "popery " must here be understood the belief that spiritual doctrines always lend themselves to a precise embodiment in black and white, and can thereafter be dealt with like so many clauses of an act of parliament.
He was removed to Carnarvon Castle, and thence to Mont Orgueil Castle in Jersey, where he occupied himself in writing against popery.
His Commentary on the Epistle to the Philippians (1618, reprinted 1864) is a specimen of his preaching before his college, and of his fiery denunciation of popery and his fearless enunciation of that Calvinism which Oxford in common with all England then prized.