Conditions of marrying more than one woman:

Islam set forth some conditions for marrying more than one woman. Those conditions are as follows:

1- To deal justly among the wives. This is limited with the human capability; it includes being just in food, clothes, housing, interest and treatment. However the Quran denotes that it is very difficult: "...if ye fear that ye shall not be able to deal justly (with them), then only one, or that which your right hands possess" (an-Nisa, 4/3). So if there is a fear that one cannot deal justly or one can oppress, then the principle of being content with one woman becomes valid. However, justice does not include issues like liking, inclination of the heart and love, because they cannot be controlled. Islam does not place a burden on man greater than he can bear. However, it is forbidden to incline to one of the wives extremely and deprive the others from love. The following is stated in a verse: "Ye are never able to do justice between wives even if it is your ardent desire: but turn not away (from a woman) altogether, so as to leave her (as it were) hanging (in the air).” (an-Nisa, 4/129).

When the two verses above are evaluated, we can draw the conclusion that polygamy is not an essential rule but a permission that can be used when extraordinary conditions are present.

2- To be able to maintain the family. In Islam, it is necessary for a man who wants to marry one woman or more to be able to meet the eating, drinking, clothing and housing expenses of her or them. The Prophet (PBUH) said the following: O young men! Those among you who can support a wife should marry " (Bukhari, Sawm, 10, Nikah, 2, 3, 19; Muslim, Nikhh, 1,3; Abu Dawud, Nikah, I; Ibn Majah, Nikah, ; Nasai, Siyam, 43). There is no doubt that the hardship of marriage lies in the expenses of the wife.

The reasons why Islam permits polygamy:

In Islam monogamy is essential and polygamy is exceptional. It can be used only when it is necessary or compulsory. Islam did not make polygamy obligatory for anybody, nor did it encourage polygamy. However, it is regarded permissible when there are some general or special reasons.

General reasons: In some regions the male population decreases and female population may increase above normal. During the time of wars it is more frequent. As a matter of fact, after the World War I in Germany, there were four or six women for one man. Then German women advocated that men should marry more than one woman. In such a situation polygamy serves to protect women from prostitution, to provide them with a warm home and to guard fatherless children.
Sometimes it may be necessary to marry more than one woman to increase the population in some regions; for instance, the death of most of the population in war.
There may be polygamy in order to spread Islam. So the Prophet was married to one woman Hazrat Khadijah until he was 54 and had 9 wives after that. (az-Zuhayli, VII, 169, 170).

There are a lot of special reasons:

1- The woman may be ill and cannot meet her husband’s sexual needs. It may be a gynecologic disease that cannot be cured; the woman may be barren and cannot bear a child. In such a case divorcing the diseased wife and marrying another may seem to be a solution but instead of sending her away from her children’s home, marrying a second woman with the consent of the first wife should be a better solution. Thus the rights of the first wife are preserved.

2- Some men may have fallen in love with another woman. The only way to prevent him from adultery is the second marriage.

So, the fact that polygamy is permissible is due to obligation, necessity, illness or a valid cause.

Love and polygamy

Islam advises spouses to love each other in a legitimate way. However, it does not want that love to be confined to this world only but to become eternal. It defines some criteria for it. One of them is to love someone for the sake of Allah, because everything depends on Allah and belongs to Him. He is the owner of all estates. He who loves the people he loves for the sake of Allah makes his love eternal and guarantees it. Death and partings cannot cause the disappearance of that love.
A man who thinks of marrying more than one woman can marry only if he is determined to act equally among his wives in terms of treatment, spending the night with, justice, clothing, meeting their necessities and other issues and if he needs a second marriage Otherwise it is not permissible. If he does not observe these conditions he will have committed a haram (a forbidden act) and violated other people’s rights.

Allah permitted marrying more than one woman in the Quran. However, it demanded monogamy in cases where there may be injustice. Therefore we can easily say that marrying more than one woman is not right unless it is obligatory. We see that treating all of the wives equally is almost impossible, at least very difficult and that not every man can do it.
However, a person who thinks that a second marriage is obligatory can marry with the presence of witnesses and it is not compulsory for him to inform his relatives about it.

POLYGAMY

"A man who has two wives and who is completely inclined to one and who ignores the other emerges with one side of his body paralyzed in the Day of Judgment." (Hadith; Ibn Majah, Nikah, 47; Mishqatl’l-masabih, 2/196)

Antique Egypt Law: A man could marry more than one woman under some circumstances.

Babel Law: according to Hammurabi laws if a woman could not bear a child or had a serious disease the husband could have a concubine.

Chinese Law: If the wealth of the husband were sufficient, he could marry secondary wives. However, the children from the secondary wives were regarded as the children of the first wife.

Antique Brahmans: According to the book Vichnou, men could marry one, two, three or more women in accordance with their classes. In the book Apastamba there was a limit; if the woman carried out her tasks and she had a male child, the husband could not marry a second woman. In the laws of Manu, the husband had to choose his first wife from the same social class; he could marry a woman of lower classes as his second wife.

Ancient Iran: Polygamy was legal.

Roman Law: It was possible to have a concubine, without a legal wedding.
The Bible: It is stated in the Old Testament that Hazrat Dawood married several women. There are some other places that mention polygamy in the Old Testament. There existed polygamy in Judaism.

In the New Testament, there is not an item prohibiting polygamy. However there are recommendations that it is better to be content with one wife.

In Christianity, polygamy was normal until the 16th century.

Arabia before Islam: There were no limitations regarding polygamy. Men could marry as many women as they wanted; sometimes they even exchanged their wives.

POLYGAMY IN ISLAM

Allah states the following:

"If ye fear that ye shall not be able to deal justly with the orphans, marry women of your choice, two, or three, or four; but if ye fear that ye shall not be able to deal justly (with them), then only one, or that which your right hands possess. That will be more suitable, to prevent you from doing injustice." (Chapter an-Nisa / 3)

It is seen clearly in the verse that marrying more than one woman 2, 3 and finally 4 is not an order that has to be carried out like fardh or wajib (compulsory) but permission. However, this permission depends on dealing justly among the wives. It is stated that being content with one wife is the closest and rightest way to justice; it is ordered that a person who fears that he won’t be able to deal justly has to be content with one wife.

PRINCIPLES OF ISLAM REGARDING POLYGAMY

1) Limitation of the number: Islam put a limitation to the limitless marriages of men during the period of Jahiliyyah (Ignorance). After Allah sent down that verse, acting on the order of the Messenger of Allah, those who had more than 4 wives divorced the extra ones.

2) Dealing justly among wives: It will be in eating, drinking, clothing, housing, intercourse and love. However, it is very difficult, almost impossible to deal justly in terms of love. Various physical and psychological characteristics will cause differences in the level of love. No matter how hard he tries to deal justly, it is almost impossible for a man to achieve it.

Allah states the following:

"Ye are never able to do justice between wives even if it is your ardent desire: but turn not away (from a woman) altogether, so as to leave her (as it were) hanging (in the air). If ye come to a friendly understanding and practice self-restraint, Allah is Oft-Forgiving Most Merciful." (Chapter an-Nisa/ 129)

In this verse, Allah exempts men from dealing absolutely justly in terms of love and liking. However, he prohibits men from inclining totally to one and ignoring the other(s), and He orders men to do their best to deal justly. The following is stated in a hadith:

"A man who has two wives and who is completely inclined to one and who ignores the other emerges with one side of his body paralyzed in the Day of Judgment." (Hadith; Ibn Majah, Nikah, 47; Mishqatl’l-masabih, 2/196)

A woman does not consent to share his husband with another woman under normal circumstances, and no woman would like to marry a married man unless she has to.
It is a necessity of belief that polygamy is right. However, to believe it does not necessarily mean for a woman to consent to the second wife and approve it.
No believer father would like his son-in-law to marry a second, third or fourth woman along with his daughter. The jealousy nature of the woman and the affection of the father prevent it. As a matter of fact,
The daughter of our Prophet, Hazrat Fatima, objected to his husband’s, Hazrat Ali’s, marrying to a second woman. If it weren’t permissible to object Hazrat Fatima, who was brought up by our Prophet, would not have objected. The Messenger of Allah would have warned her and ordered her to consent to her husband’s wish. However, it did not take place like that. On the contrary, the Messenger of Allah, who saw that his daughter was sorry, asked Hazrat Ali to give up his wish and told him that if he did not give up, he could marry another woman after divorcing Hazrat Fatima. He did not consent to Hazrat Ali’s second marriage and to depress his daughter.
By considering that act of the Messenger of Allah, it can be stated that Muslim daughters and fathers may object to the second marriage of the husband or son-in-law.

To sum up: Islam neither orders nor prohibits polygamy. It only permits it when it is necessary. There is no need to say much after narrating the happening above.

References:

1) While preparing this article we mostly referred to the book "İslamda Kadın Hakları" by Mehmet Dikmen.
2) Elmalı Interpretation (Tafseer)

@passey, is a muslim man obligated to ask his first wife for permission to marry another and what happens if she rejects it? you might need to establish the christian version of hazrat dawood in the bible to complete your write up. cheers

I disagree with the bolded.

Marrying a second wife does not have to be out of necessity. Saying that Islam only permits it out of necessity is wrong. You will need to bring clear evidences to support that and the evidences your brought don't do that. If a man can afford the costs and be fair to both wives, he is permitted to do so.

Contact17:
I disagree with the bolded.

Marrying a second wife does not have to be out of necessity. Saying that Islam only permits it out of necessity is wrong. You will need to bring clear evidences to support that and the evidences your brought don't do that. If a man can afford the costs and be fair to both wives, he is permitted to do so.

Correct