A more than 20-year veteran of the board of directors for First Horizon National Corp. has retired.

R. Brad Martin, chairman of RBM Venture Co., retired from the board of Memphis-based First Horizon — parent company of First Tennessee Bank. Martin joined the board in 1994.

“Brad has been an important member of our board for 23 years and served as lead director through the financial crisis and for several years afterward,” said Bryan Jordan, chairman and CEO of First Horizon, in a release.…