1) Tosfos above 13b DH Lechada cites the Talmud Yerushalmi that if the wife of the Cohen Gadol dies on Yom Kipur he has to marry another wife on Yom Kipur so that he can continue with the Avodah.

2) Ba'inan Simcha Gadolah is stated by Rashi 14a DH Mi as a requirement for eating Kodashim. However the requirement that the Cohen Gadol should have a wife on Yom Kipur is learnt in the Mishnah above 2a from the verse (Vayikra 16:6) "And he shall atone for himself and his wife":- His house is his wife.

3) It should be pointed out that the Tosfos Yeshanim, above 2a DH Shema, is in doubt whether it is Me'akev that the Cohen Gadol has a wife. It is possible that even if he does not have a wife, the avodah that he does is acceptable bedieved. The Tosfos Rosh 2a also writes that even though Rabbi Yehuda states that a second wife is prepared for him, this does not mean that he is invalid if he does not have a wife, but rather that the choice Mitzvah is that he has a wife but his avodah is kosher even without. In fact, whilst the Tosfos Yeshanim is in doubt on this point, it is clear to the Rosh that it is only lecatchilah. The Gevuras Ari, at the beginning of the Masechta, also discusses this question at length and his conclusion seems to be that the wife is not essential bedieved.

4) However the Rambam Hilchos Yom Hakipurim 1:2 writes that all the avodos of Yom Kipur can only be done by a married Cohen. The Meiri 2a DH veR'Yehuda writes even more clearly that "it is impossible to perform the avodah of the day unless the Cohen Gadol is married". Minchas Chinuch 185:7 also writes that the avodah is invalid even bedieved if the Cohen Gadol is not married.

Dovid Bloom