← history
Read stories →
December 4, 1563

Council of Trent

The Council of Trent formally closes

Religion
Council of Trent View full image ↗
Illustration generated by Ideogram 4 (fp8) (12 steps, 1216x832) on an NVIDIA RTX 5090 · 2026-08-29
How was this image made?

The creative brief sent to the image model. These are instructions, not a record of what actually happened.

Original prompt & settings (JSON) ↗

The last session was hurried forward after an overnight courier reported that Pope Pius IV might be dying.

4 December 1563, at Trent

The council's twenty-fifth and final session, begun on 3 December, concluded at Trent on 4 December 1563.

It had been advanced because urgent news arrived that Pius IV was dangerously ill; the legate Giovanni Morone drove the remaining business through.

On 4 December the council promulgated measures on indulgences, fasts and feast days, and the unfinished Index, catechism, breviary and missal, and addressed acceptance and observance of its decrees.

255 signatures, 39 of them deputies

The council fathers reread and approved the doctrinal decrees issued during the preceding periods, and formally requested papal confirmation of the complete body.

255 people signed the completed decrees. The final session counted 199 cardinals, archbishops and bishops, plus 3 patriarchs, 7 abbots, 7 religious superiors general and 39 deputies for absent bishops.

Formal acclamations accepted the council's faith and decrees and anathematized heresy. The presiding legates then blessed and dissolved the assembly.

Closed, but not yet confirmed

Closing and confirmation were separate events. Pope Pius IV confirmed the decrees on 26 January 1564, through Benedictus Deus.

The marriage decree Tametsi was already three weeks old — promulgated in Session 24 on 11 November 1563 — and took force only where locally promulgated and after its specified publication period.

The 4 December date is the contemporary Julian one used at Trent; its proleptic Gregorian equivalent is 14 December.

Sources

Researched 24 Aug 2026 8 sources not yet audited

How this was checked

Researched from the web into a fact sheet and rewritten from that sheet. This article has not yet had an independent model audit. How the pipeline works →

What the sources leave uncertain

  • December 4 is the contemporary Julian-calendar date used at Trent; its proleptic Gregorian equivalent is December 14.
  • The often quoted 255 is the number of signatories, including deputies for absent bishops, not simply the number of bishops physically attending.
  • The final session occupied both December 3 and 4, so measures from Session 25 should not all be assigned exclusively to the second day.

Checked against