His later marriages are better explained as political marriages to other members of his group (as in the case of his youngest wife, who he married at age six, has sex with at age 10, but no children, please note the sex at age ten was considered a requirement for a valid marriage under Arab customs which appears to be why it was done, he had no children by that wife. he died in 632
http://en.wikipedia.org/wiki/Muhammad%27s_wivesMohammad's first wife was Khadijah bint Khuwaylid who he married at age 25, she age 40. She died when he turned 50. He had no other wives while she lived. (Died c 619)
http://en.wikipedia.org/wiki/Khadijah_bint_KhuwaylidAt Khadijah's death he married Sawda bint Zama, who was still five year older then he was. I should point out while she became Mohammad's first wife on her marriage (Khadijah had died BEFORE she was married to Mohammad) it appears Mohammad married her more as a companion AND to help her in her old age since her first Husband and the father of her children was dead and that father had been a loyal follower of Mohammad. (died c674)
http://en.wikipedia.org/wiki/Sawda_bint_Zama. He then married Aisha, daughter of his follower Abu Bakr, later the First Caliph, thus this marriage is viewed as more a traditional marriage between families as an act to bring two families closer together then anything else. This is the woman Mohammad married at age 6 and had sex with at age ten. While the record says he had intercourse with her, it does NOT say whether is was actual intercourse or an act of intercourse to meet traditional Arab law (i.e. went through the motions more then any actual sexual act). (died c678, she was the last of Mohammad's wives to die)
http://en.wikipedia.org/wiki/AishaMohamed's fourth wife was Hafsa Bint Umar, daughter of another follower and another widow, through only about 20 at the time of Marriage. She was Daughter of Umar who was the Second Caliph AND whose family formed the subsequent Umayarn dynasty after the Caliphate of Ali, the Fourth Caliph and the son-in law of Mohammad. This one appears to be both Politics AND to help a widow.
http://en.wikipedia.org/wiki/Hafsa_bint_Umar (d c666)
Mohammad's Fifth wife was Zaynab bint Khuzayma, Another young widow of a fallen comrade of Mohammad, she died eights months after her marriage. (c624 AD)
http://en.wikipedia.org/wiki/Zaynab_bint_KhuzaymaWife # 6 was Umm Salama Hind bint Abi Umayya, a 40 year old Widow of a fallen soldier of the Mohammad. Another marriage to aid a widow, who had four children and no other support:
http://en.wikipedia.org/wiki/Umm_Salama_Hind_bint_Abi_UmayyaAt this point Rayhana bint Amr ibn Khunafa enters the household of Mohammad. She would have been Current Wife #5, but the records are unclear what her status was. She was Jew and no record exists of her conversion to Islam (Unlike the above, all of who were followers of Islam). She appears to have been a slave, but freed from her slavery by Mohammad. She might have been his Concubine, but some call her his wife, She died the year before he did and records are just unclear as to her status. Since Aisha, Salama, Hafsa and Sawda were still alive and not divorced from Mohammad, and no man could have more then four wives at one time, she probably was just a slave, but the exact relationship is confusing.
Mohammad's next wife was Zaynab bint Jahsh (wife # 8). She was of Arabic Aristocracy and at first Mohammad had her marry his adopted son, but that marriage lasted less then a year (c626 ad) then he married her. While various reason for this has been proposed but Mohammad was on the upswing at this point, and had already controlled most of Arabia, he would even order an attack on a Byzantine City two years later (Where his adopted city would die). She is another question mark for she would have been Marriage #5, unless Swada was divorced by Mohammad (a Possibility given the four wife rule). She died in and was the half sister of Maymuna bint al-Harith, wife # 12, who only married after Zaynab's death in 629 AD). Another half sister married Abu Bakr, who became the first Caliph after the death of Mohammad in 632 AD.
http://en.wikipedia.org/wiki/Zaynab_bint_JahshWife # 9 was Juwayriyya bint al-Harith. She had been captured in a battle over who control a part of Arabia, she was the daughter of the loser of that battle. While the official line is different, it appear Mohammad married her to try to get that tribe to support him. It apparently worked, it fact so while other enemies of her tribe freed other members of her tribe they were holding. While she was about 20 in 629, when she was captured, the politics of the situation seems to be the important factor (And again the four wife rule was ignored).
http://en.wikipedia.org/wiki/Juwayriya_bint_al-HarithWife #10 is Ramlah bint Abi Sufyan, Daughter of the leader of Mecca who opposed Mohammad for most of his life, then when it became clear Mohammad could take Mecca he arrange so it can be done without bloodshed and as part of the deal his doughier (then about age 39) would marry Mohammad (who was 58). Another marriage more for Polities then anything else. (died 666)
http://en.wikipedia.org/wiki/Ramlah_bint_Abi-SufyanWife #11, was Safiyya bint Huyayy, who was 17 at the time of her marriage, but again some confusions. Her tribe had been Jewish not Arabic, she seems to have embraced Islam but the marriage seems to be another attempt by Mohammad to get the various tribes of Arabia behind himself and Islam. Her tribe had been defeated and conquered, she herself was viewed as a product of conquest, but Mohammad married her instead of making her his slave, which under Arab rule meant she became a free woman on his death (Which was only two years away). She appears to remain a Muslim all her life, but had connections with her Jewish family even at her death (C670 ad)
Marriage #12 was Maymuna bint al-Harith, she was 36, he was 60 at the time of they marriage. She was the daughter of
The last "wife" of Mohammad was Maria al-Qibtiyya. She never had a house of her own, as would a true wife would have had under Islam, and she is believed NEVER to have converted to Islam. Some early sources do not even list her as a wife of Mohammad. She is reported to have been a gift from an Byzantine official in Egypt, but the best we can figure out is that meant the Patriarch of Alexandria but that particular patriarch did not become Patriarch till after Mohammad's death. Someone gave her to Mohammad and the name was probably added later (and incorrectly). The better explanation was she had been Captured by the Persians when they took Egypt and as the Persians pulled out of Egypt as Byzantine Empire attacked Persia, the Persian Governor sent her as a present to get support for Persia from Mohammad.
http://en.wikipedia.org/wiki/Maria_al-QibtiyyaFor more on the Governor who sent her to Mohammad:
http://en.wikipedia.org/wiki/MuqawqisMy point was while Aisha was age six at her marriage and that Marriages was consummated at age 10, the next youngest wife was 17, and two others in their 20s. The rest of his wives were over 40 when he married them. Does NOT sign like someone looking for teenagers to me (and given the politics involved, most if not all of his marriages had more to do with tribal politics then anything else.