marriage contained an agreement that the wife and the children born of the marriage will not receive anything further than what was agreed in pre-nuptials, and in some cases may have been zero, or something nominal. Separate nobility titles were given to morganatic wives of dynasts of reigning houses, but it sometimes included no true property. This sort of dower was far from the original purpose of the bride receiving a settled property from the bridegroom's clan, in order to ensure her livelihood in widowhood. The practice of morganatic marriage was most common in historical German states, where equality of birth between the spouses was considered an important principle among the reigning houses and high nobility. Morganatic marriage has not been and is not possible in jurisdictions that do not allow sufficient freedom of contracting, as it is an agreement containing that pre-emptive limitation to the inheritance and property rights of the wife and the children. Marriages have never been considered morganatic in any part of the United Kingdom. In Islam The payment from the groom to the bride is a mandatory condition for all valid Muslim marriages: a man must pay mahr to his bride. It is the duty of the husband to pay as stated in the Qu'ran (Sura Al-Nisaa’ verses 4 and 20–24), although often his family may assist, and by agreement can be in promissory form, i.e. in the event the husband pronounces talaq. It is considered a gift which the bride has to agree on. The mahr can be any value as long as it is agreed upon by both parties. When the groom gives his bride the mahr, it becomes her property. While the mahr is usually in the form of cash, it may also be real estate or a business. The mahr is of assistance to a wife in times of financial need, such as a divorce or desertion by the husband. If the mahr is in promissory form then it becomes payable if the husband initiates a (divorce). If it was previously paid, the wife is entitled to keep her mahr. However, if the woman initiates the divorce (in the procedure called khula), the circumstances of the breakup become relevant. If the divorce is sought for cause (such as abuse, illness, impotence, or infidelity), the woman is generally considered to have the right to keep the mahr; however, if the divorce is