---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-23-049068"
form_type: "8-K"
ticker: "THG"
cik: "0000944695"
company_name: "HANOVER INSURANCE GROUP, INC."
filed_at: "2023-09-21T23:59:59+00:00"
generated_at: "2026-06-10T11:38:04.255828+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.3
calibrated_materiality_score: 0.3
confidence: "high"
source: SEC EDGAR
---

# Hanover Insurance amends bylaws, plans to propose board declassification at 2024 meeting

## Summary
- Bylaws amended to add exclusive forum provision for Delaware courts and conform stockholder list rules to Delaware law.
- Board expects to propose declassification of board structure at 2024 annual meeting, moving from staggered three-year terms.
- Amendments effective September 19, 2023; declassification proposal subject to stockholder vote at 2024 annual meeting.

## SEC filing metadata
- accession: 0000950170-23-049068
- form_type: 8-K
- ticker: THG
- cik: 0000944695
- company_name: HANOVER INSURANCE GROUP, INC.
- filed_at: 2023-09-21T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.3
- calibrated_materiality_score: 0.3
- confidence: high
- sec_items: 5.03, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/944695/000095017023049068/0000950170-23-049068-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/944695/000095017023049068/thg-20230919.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-23-049068
- JSON: https://secwatch.observer/filing/0000950170-23-049068.json
- Plain text: https://secwatch.observer/filing/0000950170-23-049068.txt

## Key facts
- Governance Changes
  HANOVER INSURANCE GROUP, INC.: Amended by-laws to revise stockholder list provision and add an exclusive forum provision for certain legal actions (effective 2023-09-19).
  - Change: bylaw amendment
  - Effective: 2023-09-19
  source text: On September 19, 2023, as part of its periodic review of corporate governance matters, the board of directors (the “Board”) of the Hanover Insurance Group, Inc. (the “Company”) approved and adopted amendments to the Company’s by-laws (as so amended and restated, the “By-laws”), which became effective immediately (the “By-law Amendments”).
  evidence_url: https://www.sec.gov/Archives/edgar/data/944695/000095017023049068/0000950170-23-049068-index.htm

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.