Why Pengiran Anak Abdul Momin was chosen as the Sultan?

 

Pengiran Anak Abdul Momin was only related to the Sultan Omar Ali Saifuddien II (SOAS II) when he married to the Sultan’s daughter Raja Isteri Pengiran Anak Zubaidah and that made him the son-in-law of SOAS II. On top of that, he was not the first choice candidate to be chosen as the Sultan. In fact it was the brother of SOAS II, Pengiran  Anak Muhammad Tajuddien who was the first choice candidate.  So how come this son-in-law of SOAS II became the successor?