Hindu and Punjabi weddings have several awesome and unbelievable rituals. The best part is, it's well associated and defined on basis of science.
A sarbala, in certain wedding customs from the Indian subcontinent, is a nephew or cousin of the groom who accompanies the groom during the ceremony as his protector (caution: war zone). The sarbala can also be the "future groom's" brother in law.
The word "sarbala" (Punjabi), "shahbala" (Urdu) is derived from Sanskrit which means associate groom.
The sarbala often wears a similar outfit to the groom and rides a horse. The tradition is most common in Hindu weddings but may also be part of Muslim or Sikh ceremonies.
This one is interesting, be cautious...
In past times, a baraat or a marriage procession would go to the bride's village for the marriage ceremony carrying gold and valuable gifts. An attack of robbers on the baraat or the marriage procession was a common occurrence at those times where the robbers would kill everyone in the procession and rob the valuables.
The Sarbala was usually the younger brother or a cousin of the groom who assured the safety of the Groom. And during this process, if anything was to happen to the groom the sarbala would take his place and continue the wedding.
Seriously, Indian customs are so interesting. So much of varieties of everything, and it never stops amazing us.