Complex sentence: The ministers of the Kirk, whose influence in Scotland was too extensive for the king to neglect, were only with the greatest difficulty persuaded to accept James's account of the occurrence, although he voluntarily submitted himself to cross-examination by one of their number.
Split into simpler sentences: The ministers of the Kirk, whose influence in Scotland was too extensive for the king to neglect, were persuaded, but with great difficulty, to accept James's account of the occurrence. He voluntarily submitted himself to cross-examination by one of their number.