X0306 4 2017-11-29 0000944695 HANOVER INSURANCE GROUP, INC. THG 0001690677 Keim Mark Lowell C/O THE HANOVER INSURANCE GROUP, INC. 440 LINCOLN STREET WORCESTER MA 01653 0 1 0 0 Executive Vice President Common Stock 2017-11-29 4 M 0 4966 85.30 A 4966 D Common Stock 2017-11-29 4 S 0 4966 107.801 D 0 D Common Stock Option (right to buy) 85.30 2017-11-29 4 M 0 4966 0 D 2026-11-21 Common Stock 4966 9934 D The price reported in Column 4 is a weighted average price. These shares were sold in multiple prices ranging from $107.71 to $107.85, inclusive. The Reporting Person undertakes to provide The Hanover Insurance Group, Inc. ("THG"), any security holder of THG, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range set forth above. The option, representing the right to purchase a total of 14,900 shares, was granted on 11/21/16, vested 1/3 on 11/21/17, and a 1/3 will vest on each of the second and third anniversaries of the date of grant. /s/ Matthew R. Frascella pursuant to Confirming Statement 2017-11-30