A Kohen Gadol may not marry a widow, neither a widow from betrothal nor a widow from marriage. And he may not marry a bogeres; R' Elazar and R' Shimon [however] validate [marriage] with a bogeres. He may not marry the victim of a blow.  [If] he betrothed a widow and was [then] appointed Kohen Gadol, he may marry [her]. It happened that Yehoshua ben Gamla betrothed Marsa, the daughter of Baisos, and the king [then] appointed him to be Kohen Gadol, and he married her.  [If] a widow awaiting her yavam fell to an ordinary Kohen, and he was [then] appointed to be Kohen Gadol, even if he [had already] performed maamar with her, he may not marry [her]. [If] a Kohen Gadol's brother died, he performs chalitzah, but not yibum.

An ordinary Kohen may not marry an ailonis, unless he has a wife or children. R' Yehudah says: Even if he has a wife or children he may not marry an ailonis, because she is the zonah mentioned in the Torah. The Sages, however, say: Zonah refers only to a female convert, or a freed slavewoman, or one who engaged in a forbidden cohabitation.