During the time of the Talmud, people would show signs of mourning over the passing of others aside from immediate relatives, like members of the leadership of the Jewish people – the Nasi, the Hakham and the Av Bet Din. When any of these leaders passed away, halitzat katef was required.
Halitzat katef is actually a symbolic tearing of the clothes, an indication that the person has removed his garment from his shoulder due to aveilut (mourning). As is clear in the Gemara, the more severe the aveilut – and the greater the desire to show respect to the deceased – the more the garment is removed. For the Hakham it is removed from the right side (which was not all that unusual in normal activities and might not be recognized as an act of mourning); for the Av Bet Din, it is removed from the left, and for the Nasi it is removed from both shoulders.
The Hakham (when not used as an honorific title) has two meanings. In certain cases it refers to the community or synagogue Rabbi, but in our case it appears to refer to an individual with greater responsibility, someone involved in the central Rabbinic court system, which was the continuation of the Sanhedrin. The head of the court was the Nasi, who, at that time, was a descendant of Hillel the Elder and was viewed as the leader of the Jewish community in Israel. The Nesi’im, who also represented the community before the foreign rulers, saw themselves as the symbolic continuation of the Davidic monarchy, and the respect granted them stemmed not primarily from their Torah knowledge, but because they were the representatives of autonomous Jewish rule in Israel. The Av Bet Din was second to the Nasi as far as his standing in the community was concerned, and he served as the acting head of the central Jewish court system.