There is a lot of misunderstanding about polygamy under Islam.
Allah says in the Holy Qur'an:
"Marry women of your choice, two, or three, or four; but if you fear that you shall not be able to deal justly (with them), then only one." Al-Quran (4:3)
Islam does allow having more than one wife, but it has set strict conditions, the most important being that the husband should be fair with all his wives, and treat them equally, which in practice is very difficult.
If a man has more than one wife, he must treat them all in an equal manner, emotionally and financially. For example, he has to provide separate living accommodation for each of his wives. Due to the difficulty in ensuring equality and the financial burden, most Muslim men do not have more than one wife.
Actually, the reason for multiple wives in Islam was not to satisfy mens desires, but for the welfare of the widows and the orphans of the wars. During war times, many women are unable to find husbands, and some prefer to be a co-wife rather than single.
Also, Islam prohibits men from cheating on their wives, which also means that a man can't marry another woman without the knowledge of his wife. He is obliged to inform her and if she disagrees she can ask for a divorce.
Polygamy is not restricted to Islam either Gilly.
