Muhammad
Muhammad's life is traditionally defined into two periods: pre-hijra (emigration) in Mecca (from 570 to 622), and post-hijra in Medina (from 622 until 632). Muhammad is said to have had thirteen wives in total (although two have ambiguous accounts, Rayhana bint Zayd and Maria al-Qibtiyya, as wife or concubine.) Eleven of the thirteen marriages occurred after the migration to Medina.
Muhammad Hussain Najafi
Before going to Najaf for higher religious education, he was married to his maternal cousin in 1952. His teacher Allama Yar Shah had links with ulema of Najaf, and he wanted Muhammad Hussain to get married in a scholarly family of Najaf, but Muhammad Hussain declined this proposal due to cultural differences.
In 1954, his only son Muhammad Sibtain was born. At the age of five, he got seriously ill and died, as Muhammad Hussain did not have enough money for his treatment. (Muhammad Hussain used to spend his stipend money on household and buying books.) 
After Sibtain's death, Ayatollah Najafi did not have children for next eleven years. He married the daughter of Haji Muhammad Shafi (Faisalabad) in 1970. He had three daughters from this marriage. His first wife died in 1996.