Principal Financial Group, Inc. announced that H. Elizabeth Mitchell, former president and chief executive officer of Renaissance Reinsurance U.S., has been elected to the Principal Board of Directors. Mitchell retired as President and CEO of Renaissance in 2016 after joining the company as part of an acquisition of Platinum Underwriters Reinsurance Inc., a property, casualty, and health reinsurance firm, where she had served as President and CEO for 10 years.