The Bakil are one of the tribal federations of Yemen that go back to pre-islamic times along with the Hashid tribe. We have had photo of the late Shiek of Sheiks, Abdullah Hussain Al-Ahmar's Jambiya posted awhile back. Both federations were primarily Zaidi though nowadays the majority of the population in Yemen is Sunni.

Salaams Michael Blalock ~Thank you for that detail ... I was backtracking generally looking for this sort of Neillo decoration and stumbled onto http://www.vikingsword.com/vb/showthread.php?t=11437 and wanted to copy a key picture on your thread kindly placed by Steve..and to place your thread as a reference. :shrug:
Regards,
Ibrahiim al Balooshi.

The niello work on the shaikh's jambiya is different from the older Yemeni made ones.

http://oriental-arms.com/photos.php?id=1203

This is an Iraqi gdaimi with identical decoration to the shaikh jambiya, the style is defined by scenery generally of al ahwar and the rivers dejla and furat and other Iraqi monuments.