Exhibit 21.1 Subsidiaries of the Registrant The following companies are subsidiaries of the Registrant as of December 31, 1998. JURISDICTION OF PERCENTAGE NAME INCORPORATION OWNERSHIP - ----- ---------------- ----------- Illinois 100% RLI Aviation, Inc. Illinois 100% Replacement Lens Inc. Illinois 100% Mt. Hawley Insurance Company Kansas 100% RLI Insurance Ltd. Bermuda 100% RLI Insurance Agency Ltd. Canada 100% RLI Mortgage Services, LLC Illinois 50% RLI Texas Corp. Texas 100%