Enstar Group Ltd. is a holding company, which engages in the acquisition and management of insurance and reinsurance companies. It operates through the following segments: Non-life Run-off, Atrium, StarStone, and Other. The Non-life Run-off segment operates through its subsidiaries that run off their property and casualty and other non-life lines of business. The Atrium segment consists active underwriting operations and financial results of Northshore, a holding company that owns Atrium and its subsidiaries and Arden. The StarStone segment focuses in the active underwriting operations and financial results of StarStone and StarStone Specialty Holdings Limited, a holding company that owns StarStone and its subsidiaries. The company was founded by Paul James O'Shea, Nicholas A. Packer and Dominic Francis Michael Silvester in August 2001 and is headquartered in Hamilton, Bermuda.