The emergence of self-sufficient local units of production is also indicated by the gradual decay of urban centres in the Gupta period. Archaeology shows that Kushana layers belonging to the first-third centuries AD were very flourishing. On the other hand the Gupta layers belonging to the fourth-sixth centuries AD were in state of decline and in many cases Kushana bricks were used in Gupta structures. In many urban sites habitation disappeared after the 6th century AD.
The fourth one includes the Daivapura Shahanushahs, Saka Murundas and the dwellers of Sinhala and all other islands who offered their person for service to Samudragupta. Harisena the court poet of Samudragupta lays special emphasis upon Samudragupta's learning and wisdom, sharp and polished intellect and above all his poetical and musical talents. He also refers to Samudragupta's charity and kindness even to conquered kings. The variety of gold coins issued by Samudragupta not only indicate the power, wealth and grandeur of his empire but also give us some idea of his appearance and insight into his personal qualities. The Guptas were followers of the Brahmanical religion and Samudragupta fully maintained the tradition of religious toleration.