X0306 4 2022-02-04 0000944695 HANOVER INSURANCE GROUP, INC. THG 0001576903 Welzenbach Mark Joseph C/O THE HANOVER INSURANCE GROUP, INC. 440 LINCOLN STREET WORCESTER MA 01653 0 1 0 0 Executive Vice President Common Stock 2022-02-04 4 M 0 10377.00 104.110 A 30419.077 D Common Stock 2022-02-04 4 S 0 10377.00 138.50 D 20042.077 D Common Stock 2022-02-04 4 M 0 4686.00 117.220 A 24728.077 D Common Stock 2022-02-04 4 S 0 4686.00 140.4246 D 20042.077 D Common Stock Option (right to buy) 104.110 2022-02-04 4 M 0 10377.00 0 D 2028-02-27 Common Stock 10377 0 D Common Stock Option (right to buy) 117.220 2022-02-04 4 M 0 4686.00 0 D 2029-03-05 Common Stock 4686 2343 D The price reported in Column 4 is a weighted average price. The shares were sold at multiple prices ranging from $140.11 to $140.55. 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 15,566 shares, vested 1/3 on each of 2/27/19, 2/27/20 and 2/27/21. The option, representing the right to purchase a total of 7,029 shares, vested 1/3 on each of 3/05/20 and 3/05/21 and the remaining 1/3 shall vest on 3/05/22. /s/ Matthew R. Frascella pursuant to Confirming Statement 2022-02-08