On this date in 1529, Zwinglian missionary Jacob Kaiser was burnt at the stake in the Catholic Swiss canton of Schwyz.
This otherwise routine Reformation martyrdom led Ulrich Zwingli, then Grossmünster of Zurich, to make war on the Catholic cantons, seeking to pry them open for further Protestant inroads.
Let us be firm and fear not to take up arms. This peace, which some desire so much, is not peace, but war; while the war that we call for, is not war, but peace. We thirst for no man’s blood, but we will cut the nerves of the oligarchy. If we shun it, the truth of the gospel and the ministers’ lives will never be secure among us.
–Zwingli, channeling Orwell
The short-lived Erster Kappelerkrieg — the First War of Kappel — was won within weeks, swiftly concluded by a truce favorable to Zwingli’s Protestant alliance.
(Legend has it that the treaty was concluded over a shared pot of milk soup picturesquely resting on the Catholic-Protestant border, the Kappeler Milchsuppe.)
But this initially favorable return on poor Jacob Kaiser’s sacrifice was soon squandered.
Hostilities between the two camps continued, eventually flaring into the Second War of Kappel. Zwingli was again spoiling for the fight, but his under-prepared Protestants were trounced by a Catholic league in October 1531. Zwingli himself died on the battlefield.