Initially, in the old days it was the monks wore shabby clothes the poor, so there was such a name. It is believed that it has Eastern origin and that that such a garment worn by Jesus Christ.
Today, there are robes Greek, Russian and polugrecheskogo cut. In the West, similar robes called "habitus" - "outfit" in Latin.
The right to wear the robe gets a novice who has attained the first stage of monasticism. The monks wear black robes, and for the rest of the clergy, they can be of different colors. Cassock worn on the cassock.