A number of the nation’s longest-serving deans are soon to leave their posts, which means a lot of institutional knowledge is retiring—or at least moving out of the dean’s suite.

The average tenure of a law dean is currently about four years, according to a database maintained by Jim Rosenblatt, a professor at Mississippi College School of Law (and former dean). According to that database, two of the five longest-serving deans are soon to step down, and a third left the deanship at the end of the previous academic year.