Gemara

(Mishnah): One cannot force (his household) to leave Eretz Yisrael...

Kesuvos 110b (Mishnah): Anyone can force (his household) to ascend to Eretz Yisrael, but cannot force to leave (Eretz Yisrael). Anyone can force to ascend to Yerushalayim, but cannot force to leave. This applies to men and women equally.

'Anyone can force' (to ascend) includes slaves. According to the opinion that the Mishnah explicitly lists slaves, it includes even from a nice place to a bad place.

'Anyone can force to ascend to Yerushalayim' includes even from a nice place to a bad place. 'But cannot force to leave' includes even from a bad place to a nice place. (This is no Chidush, for anyone can force to go to Yerushalayim, even to a bad place!) This is taught for parallel structure with the Reisha.

(Beraisa): If he wants to go to Eretz Yisrael, and his wife does not, she must go, or else he may divorce her without paying her Kesuvah. If she wants to go to Eretz Yisrael and he does not, he must go, or divorce her and pay her Kesuvah;

If she wants to leave Eretz Yisrael, and he does not, she must stay, or else he may divorce her without a Kesuvah. If he wants to leave Eretz Yisrael and she does not, he must stay, or divorce her and pay her Kesuvah.

110a (Mishnah): There are three regions (of Eretz Yisrael) regarding marriage: Yehudah, Ever ha'Yarden and Galil. One cannot force his wife to move to a different region. Within a region, he can force her to move from a city to a similar size city, but not from a city to a big city, or vice-versa. One can force his wife to move from a bad place to a nice place, but not from a nice place to a bad place;

R. Shimon ben Gamliel says, he cannot force her even from a bad place to a nice place, because living in a nice place is Bodek (tests).

(Gemara): R. Shimon ben Gamliel's law is like Shmuel's teaching, that change in one's routine brings stomach sickness.

Rishonim

The Rif and Rosh (Kesuvos 13:17,18) bring the Mishnayos and Gemara verbatim, just the Rif omits R. Shimon ben Gamliel's opinion.

Rif and Rosh: A Tosefta teaches that one can force (his household) to move from a city that is mostly Nochrim to a city that is mostly Yisrael, but not vice-versa.

Rambam (Hilchos Ishus 13:16): The entire inhabited world is composed of lands, e.g. Kena'an, Mitzrayim, Teiman... Regarding marriage there are three lands of Eretz Yisrael: Yehudah, Ever ha'Yarden, and Galil.

Rambam (17): If one married a woman in a different land, she goes to live with him, or he divorces her without a Kesuvah. He married her on this Tanai, even though he did not specify.

Rambam (18): He can force her to go from one city or village to another, but not from a good place to a bad place or vice-versa, for she must endeavor and check herself well in a good place, lest she be trifling and ugly. He cannot force her to go from a place that is mostly Yisrael to a place that is mostly Nochrim, but he can force her vice-versa.

Ran (DH Masnisin): The Rambam says that in a good place she must endeavor (to look nice) and check herself, lest she be in his eyes trifling and ugly. He explains that Shmuel's teaching was brought merely for an example that a change for the good sometimes causes harm.

Rambam (19): This discusses moving within Chutz la'Aretz or within Eretz Yisrael. From Chutz la'Aretz to Eretz Yisrael we force even from a good place of (mostly) Yisre'elim to a bad place of (mostly) Nochrim. One cannot force to leave Eretz Yisrael, even from a bad place of Nochrim to a good place of Yisre'elim.

Rambam (20): If he wants to ascend to Eretz Yisrael and she does not, he divorces her without a Kesuvah. If she wants to ascend and he does not, he divorces her with a Kesuvah. The same applies to going from any place in Eretz Yisrael to Yerushalayim. Anyone can force to go to Eretz Yisrael, but not to leave. Anyone can force to go to Yerushalayim, but not to leave.

Rabbeinu Meir (brought in Rosh): The Yerushalmi connotes that he has more rights than her! It says that he can force her to go to Eretz Yisrael or Yerushalayim, but she cannot force him. We do not force a man to follow a woman to Eretz Yisrael or Yerushalayim. This is unlike the Bavli. The Yerushalmi discusses nowadays. The Mishnah discusses when the Mikdash stood.

Rebuttal (Tur EH 75): If the Yerushalmi discusses nowadays, why can he force her? Rather, it seems that we do not distinguish nowadays from the time of the Mikdash, like the simple reading of our Mishnah.

Defense (Beis Yosef DH Yerushalmi and DH v'Yesh Omrim): Really, the Yerushalmi discusses nowadays. Chachamim did not want to diminish the man's rights regarding Eretz Yisrael and Yerushalayim. Why did the Tur bring both Rabbeinu Meir and R. Tam without saying that they argue?

Rosh: The Rif rules unlike R. Shimon ben Gamliel. Therefore, he omitted his opinion. R. Tam and the Ri rule like R. Yochanan, who always rules like R. Shimon ben Gamliel in the Mishnah, with three exceptions; this is not one of the three. Some say that the Halachah follows R. Shimon ben Gamliel because we support him from Shmuel's teaching.

Poskim

Shulchan Aruch (EH 75:1): There are three lands of Eretz Yisrael for marriage: Yehudah, Ever ha'Yarden, and Galil. The inhabited world is composed of lands, e.g. Kena'an, Mitzrayim, Teiman... (Rema - they speak different languages).

Maharam (117, cited in Darchei Moshe 2): The distinction of lands depends only on speaking different languages. If Laziya, Rinus and Frankin would be considered distinct lands (due to their size), how can it be that they are three, and Eretz Yisrael, which is 400 Parsa'os by 400 Parsa'os, was only three?!

Beis Shmuel (1): We must say that Laziya, Rinus and Frankin spoke different languages. The Rivash (176) says that one cannot force his wife to move to another kingdom. Presumably, he does not argue with Maharam. Rather, Maharam discusses places within one kingdom.

Chelkas Mechokek (1): Yehudah, Ever ha'Yarden, and Galil all spoke Lashon ha'Kodesh, but perhaps there was a difference. People of Galil did not speak precisely (Eruvin 53a). It does not depend only on language, for presumably Laziya, Rinus and Frankin do not speak exactly the same. Rather, it (also) depends on area. It is not clear what is called a different land nowadays.

Shulchan Aruch (2): When he forces her to go from one city or village to another, he cannot force her to go from a good place to a bad place or vice-versa.

Chelkas Mechokek (11): This is only if both of them are from the same city. If she is from a different land, he can force her to go even to a different size city, even from a good place to a bad place.

Shulchan Aruch (ibid.): He cannot force her to move from a place of (mostly) Yisre'elim to a place of Nochrim, but vice-versa, we always force.

Chelkas Mechokek (12): He can force her even from a good place to a bad place, for a place that is mostly Nochrim is as bad as any drawback. The Bach says that she can force him. This is wrong.

Shulchan Aruch (3): This discusses moving within Chutz la'Aretz or within Eretz Yisrael. From Chutz la'Aretz to Eretz Yisrael we force even from a good place of (mostly) Yisre'elim to a bad place of (mostly) Nochrim. One cannot force to leave Eretz Yisrael, even from a bad place of Nochrim to a good place of Yisre'elim.

Chelkas Mechokek (16): The Tur and Rambam do not say 'we force her', for even she can force him.

Shulchan Aruch (4): If he wants to ascend to Eretz Yisrael and she does not, he divorces her without a Kesuvah. If she wants to ascend and he does not, he divorces her with a Kesuvah. The same applies to going from any place in Eretz Yisrael to Yerushalayim. Anyone can force to go to Eretz Yisrael, but not to leave. Anyone can force to go to Yerushalayim, but not to leave.