Bhai Piara, a Randhawa Jat, was a devoted Sikh of the time of Guru Hargobind. When the Guru was under detention in the Gwalior Fort, Baba Buddha once went there to see him, assigning Bhai Piara to the service vice of Har mandir Sahib during his absence.
Reference:-
- The Encyclopedia Of Sikhism – Volume III