The United Nations (UN) Convention on the Rights of the Child defines a child as anyone under the age of 18 unless adulthood is legally attained earlier under the applicable country law. Thus, with some exceptions, “child marriages” are generally understood to mean marriages taking place before age 18. This 2008 brief focuses on the betrothal and marriage of girls ages 14 and younger, who are especially vulnerable to violations of their health and rights, and considers such marriages forced because girls this young rarely have the legal capacity or the personal agency to disobey their elders or to give or withhold their consent.