RenaissanceRe is a global provider of reinsurance and insurance. We provide property, casualty and specialty reinsurance and certain insurance solutions to customers, principally through intermediaries. Established in 1993, we have offices in Bermuda, Ireland, Singapore, Switzerland, the United Kingdom (the "U.K."), and the U.S. Our operating subsidiaries include Renaissance Reinsurance, Renaissance Reinsurance U.S. Inc. ("Renaissance Reinsurance U.S."), RenaissanceRe Specialty U.S. Ltd. ("RenaissanceRe Specialty U.S."), Renaissance Reinsurance of Europe Unlimited Company ("Renaissance Reinsurance of Europe") and our Lloyd's syndicate, RenaissanceRe Syndicate 1458 ("Syndicate 1458"). We also underwrite reinsurance on behalf of joint ventures, including Top Layer Reinsurance Ltd. ("Top Layer Re"), Upsilon RFO Re Ltd. ("Upsilon RFO"), DaVinci Reinsurance Ltd. ("DaVinci"), Vermeer Reinsurance Ltd. ("Vermeer") and Fibonacci Reinsurance Ltd. ("Fibonacci Re"). In addition, through RenaissanceRe Medici Fund Ltd. ("Medici"), we invest in various insurance based investment instruments that have returns primarily tied to property catastrophe risk.
We aspire to be the world's best underwriter by matching well-structured risks with efficient sources of capital and our mission is to produce superior returns for our shareholders over the long term. We seek to accomplish these goals by being a trusted, long-term partner to our customers for assessing and managing risk, delivering responsive and innovative solutions, leveraging our core capabilities of risk assessment and information management, investing in these core capabilities in order to serve our customers across the cycles that have historically characterized our markets and keeping our promises. Our strategy focuses on superior risk selection, superior customer relationships and superior capital management. We provide value to our customers and joint venture partners in the form of financial security, innovative products, and responsive service. We are known as a leader in paying valid claims promptly. We principally measure our financial success through long-term growth in tangible book value per common share plus the change in accumulated dividends, which we believe is the most appropriate measure of our financial performance and in respect of which we believe we have delivered superior performance over time.
Our core products include property, casualty and specialty reinsurance and certain insurance products principally distributed through intermediaries, with whom we seek to cultivate strong long-term relationships. We believe we have been one of the world's leading providers of catastrophe reinsurance since our founding. In recent years, through the strategic execution of a number of initiatives, including organic growth and acquisitions, we have expanded our casualty and specialty platform and products and believe we are a leader in certain casualty and specialty lines of business. We have determined our business consists of the following reportable segments: (1) Property, which is comprised of catastrophe and other property reinsurance and insurance written on behalf of our operating subsidiaries and certain joint ventures managed by our ventures unit, and (2) Casualty and Specialty, which is comprised of casualty and specialty reinsurance and insurance written on behalf of our operating subsidiaries and certain joint ventures managed by our ventures unit.