According to Antonia Fraser gunpowder was relatively easy to purchase on "the black market" from soldiers. In particular officers who supervised powder mills sold gunpowder in order to supplement their income. This sort of graft in the supply of the military wasn't unheard of, and in some areas was considered one of the "perks" of the job.

Related question. A now-deleted comment suggested something like "historians think the plot was made up, and was just an attempt to discredit Catholics."

This sounds like absolute baloney, but is there actually disagreement about the plot's existence in modern scholarship?

What was the relationship between the plot and Ireland; the lead up , the events, the participants and the reaction after?