Occultation
During the same year that al-Ḥākim disappeared in 1021, Hamza went into retreat and delegated the third leading figure, Baha'u d-Dīn as-Samuqī ("al-Muqtana Baha’ud-Dīn") to continue the missionary movement. Baha'u d-Dīn continued public preaching with the approval of Hamza, who was in a disclosed location known only to Baha'u d-Dīn and few other missionaries. Preaching was halted after the Druze sect was closed in 1043 by Baha'u d-Dīn.
Read more about this topic: Hamza Ibn-'Ali Ibn-Ahmad