EXHIBIT 21.1 SUBSIDIARIES OF TRENWICK GROUP INC. Name of Subsidiary Jurisdiction of Incorporation Trenwick America Corporation Delaware Trenwick America Reinsurance Corporation Connecticut (subsidiary of Trenwick America Corporation) Trenwick Holdings Limited United Kingdom Trenwick International Limited United Kingdom (subsidiary of Trenwick Holdings Limited) Chartwell Re Holdings Corporation Delaware Chartwell Reinsurance Company Minnesota The Insurance Corporation of New York New York