While Scotland and England were preparing for the First Bishops' War, Henderson drew up two papers, entitled respectively "The Remonstrance of the Nobility" and "Instructions for Defensive Arms". The first of these documents he published himself; the second was published against his wish by John Corbet, a deposed minister. The text was written in haste in 1639 and is reported to have been lifted from a work by Johannes Althusius to provide justification for bearing arms.