Intro
Mirza Wasim Ahmad, also spelled as Mirza Waseem Ahmad (Mian Waseem) was one of 23 sons of Mirza Basheer ud Din Mahmud Ahmad.  His mother was from Saudi Arabia, her name was Azizah Begum also called Umm Wassim (mother of wassim).  The Khalifa Married her in 1926, she was the daughter of Seth Abu Bakr Yousaf of Jeddah, Saudi Arabia.  According to tareekh ahmadiyyat, vol 4 page 554, it goes “Hazrat Khalifa tul Masih 5th Nikah was 1st Feb 1926, also published in the Alfazal of 5th Feb 1926.  The Khalifa claims that Seth Abu Bakr of Jeddah was a business man who had written to the Khalifa in 1914 in terms of marriage for his daughter, the Khalifa agreed 10 years later, and was finally married in 1926, the details and logistics are unknown (See Fazl e Omar, online english edition).  Was this arab even an Ahmadi?

His children ?
The only daughter that we have heard of is Amtul Rauf.  His brother, Mirza Naeem Ahmad is also missing from the scene.

1947
He was told and forced to stay in Qadian, India by his father.  It is unclear whether his mother stayed. He was thus amongst the dervishes of Qadian.  The Khalifa is said to have left 313 males behind in Qadian as he left for Pakistan.  Mirza Waeem Ahmad was thus the only son and member of the Mirza family to remain in India after the partition.

1947–1951
Mirza Wasim Ahmad married his aunty, Amtul Qudoos, she was the daughter of Dr. Mir Muhammad Ismail.  She was Mirza Waseem Ahmad’s father’s (the Khalifa) maternal first cousin.  It is reported by Ahmadiyya sources that Mirza Waseem Ahmad came to Rabwah to get married, he then hurriedly returned to Qadian, India.  This is very strange since in those days travelling back and forth from Pak to India was nearly impossible, Zafrullah Khan might have stepped in and made it happen.  Ahmadiyya sources report that in these days food at Qadian was scarce.

1952
Amma Jan (the wife of MGA) also known as Nusrat jehan Begum died in Rabwah.  Mirza Wasim Ahmad was not allowed to travel to Pakistan for the funeral.

1965
His father, the Khalifa, Mirza Basheer ud Din Mahmud Ahmad dies.  He is not able to travel to Pakistan for the funeral but gathers all Ahmadi’s at Qadian and makes speeches.  All communications with Rabwah was broken, as a result of war between India and Pakistan.

1971
When the situation between India and Pakistan worsened again, certain elements tried to drive out the Ahmadi population of Qadian, albeit with cunning. Mian Waseem gathered everyone in Masjid Mubarak and addressed them in an ardently anguished tone saying that Qadian was their permanent centre and that they would most certainly not leave it.  He said we have one night to pray extremely fervently and supplicate ardently to God. Not even a single child should leave Qadian of his/her own accord. I shall not leave either; officials will have to drag me out of here. Each one of you should say we do not want to leave Qadian.  That night entire Qadian supplicated and beseeched to God, in each nook and cranny earnest prayers were made. The anguished supplication of the dervishes gained acceptance with Allah. The next day, they met up with officials and had discussions. Later the officials came to inspect Qadian and then cancelled the plan to remove people.

1977
He was made as totally in-charge of Qadian.  In Urdu he was the Nazir Aala & Ameer Jamaat Ahmadiyya Qadian until his death.  The first Ameer in Qadian was the late Hazrat Maulvi Abdur Rahman.

1984, when the Khalifa died at Rabwah
Mian Waseem’s daughter Amatul Rauf says that her father’s ardent devotion to Khilafat was such that although he was unable to go to the funeral of Khalifa tul Masih III,  he wrote a letter the day after his passing away and gave it to his wife and daughter to read. In the letter he had signed his pledge of allegiance (baiat) to the Khalifa tul Masih IV not knowing who he was going to be. He explained that his baiat was not be based on his knowledge of the individual; rather his baiat was for the Khalifa of the Promised Messiah.

December 26th – December 28th 2003
He gave the inaugural address at the 2003 Jalsa Qadian.

He died in 2007
The 5th Khalifa did a tribute Friday Sermon about Mirza Wasim Ahmad.

Links and Related Essays

http://www.jalsasalana.org/qadian/2003/index.html

https://ahmadiyyafactcheckblog.com/2018/02/23/mirza-basheer-uddin-mahmud-ahmad-had-20-children-with-7-wives/

Migration from Qadian