OB

Onebeacon Insurance Group, Ltd.

A U.S. specialty property-and-casualty insurer, OneBeacon covered complex commercial risks like management liability, environmental, and entertainment insurance, sold through independent agents and brokers. It was born in 2001 when White Mountains bought the U.S. business of CGU, and it traced roots back to 1831 through the Potomac Fire Insurance Company. Its name came from its Boston headquarters at One Beacon Street — chosen after nearly 2,000 name suggestions — and was meant to evoke a guiding light for policyholders.