In some countries, the younger the bride, the higher the price she may fetch.
This practice creates an economic incentive where girls are sought and married early by her family to the highest bidder.
Bride's families would seek out any available bachelors and marry them to their daughters, before events beyond their control moved the boy away.
Persecution and displacement of Roma and Jewish people in Europe, colonial campaigns to get slaves from various ethnic groups in West Africa across the Atlantic for plantations, Islamic campaigns to get Hindu slaves from India across Afghanistan's Hindu Kush as property and for work, were some of the historical events that increased the practice of child marriage before the 19th century.
In this context, it is important to remember that in halakha, the term ‘minor’ refers to a girl under twelve years and a day.
A girl aged twelve and a half was already considered an adult in all respects.” Some Islamic marriage practices have permitted marriage of girls below the age of 10, because Shariat law is based in part on the life and practices of Muhammad, the Prophet, as described in part in Sahih Bukhari and Sahih Muslim.
Muhammad married Aisha, his third wife, when she was about age six, Some mainstream Islamic scholars have suggested that it is not the chronological age that matters; marriageable age under Muslim religious law is the age when the guardians of the girl feel she has reached sexual maturity.
This practice intensified after the Jewish community was expelled from Spain, and resettled in the Ottoman Empire.
Child marriages among the Eastern Sephardic Jews continued through the 18th century in Islamic majority regions.