This background note discusses the evolution, use, and prevalence of staggered boards. By comparison with unitary boards whose members are all elected annually for one-year terms, staggered boards are divided into subsets of directors, with one subset up for election each year, typically for three year terms. While 61% of the S&P 500 had staggered boards in 2002, the practice largely fell out of favor in ensuing decades, and only 12% had one in 2022. This note discusses what staggered boards are and how they evolved; arguments for and against them from critics and proponents; developments leading to their decline; the academic research on their potential effects broadly and on certain types of firms; and the legal approaches to staggered boards in the United States as well as the diverse approaches to staggered boards internationally.