W. R. Berkley Corporation, an insurance holding company, operates as a commercial line writer worldwide. The company operates through Insurance and Reinsurance & Monoline Excess segments. The Insurance segment underwrites commercial insurance business, including excess and surplus lines, admitted lines, and specialty personal lines. This segment also provides accident and health insurance and reinsurance products; insurance for commercial risks; casualty and specialty environmental products; insurance coverages for fine arts and jewelry exposures; excess liability and inland marine coverage for small to medium-sized insureds; and commercial general liability, umbrella, professional liability, directors and officers, commercial property, and surety products, as well as products for technology, and life sciences and travel industries. In addition, it offers cyber risk solutions; crime and fidelity insurance products; medical professional coverages; workers’ compensation insurance products; management liability and general insurance products; personal lines insurance solutions, including home, condo/co-op, auto, fine arts and collectibles, liability, collector vehicle, and recreational marine; law enforcement, public officials and educator's legal, and employment practices liability, as well as incidental medical, property, and crime insurance products; at-risk and alternative risk insurance program management services; professional liability; energy and marine risks; and insurance products to the Lloyd's marketplace. The Reinsurance & Monoline Excess segment provides treaty and facultative reinsurance solutions; property and casualty reinsurance products; facultative reinsurance products include automatic, semi-automatic, and individual risk assumed reinsurance; and turnkey products, such as cyber, employment practices liability insurance, liquor liability insurance and violent events. The company was founded in 1967 and is headquartered in Greenwich, Connecticut.