A Wireless Sensor Network (WSN) is a wireless network consisting of spatially distributed autonomous sensors to monitor physical or environmental conditions. The battery power in these sensor nodes plays an important role in increasing the lifespan of the nodes. Hierarchical routing protocols are the best known protocols to minimize the energy consumption. Low-Energy Adaptive Clustering Hierarchy (LEACH) is a classical cluster based routing protocol for WSNs having good performance, energy efficiency and effective in prolonging the network life time by consuming a small percentage of the total dissipated energy in the system. This paper surveys the state-of art of different hierarchical routing protocols that have been developed from the LEACH.