The period covered by the extant literature of the Sangam is unfortunately not easy to determine with any measure of certainty. Except the longer epics "Silappatikaram" and "Manimekalai", which by common consent belong to the age later than the Sangam age, the poems have reached us in the forms of systematic anthologies. Each individual poem has generally attached to it a colophon on the authorship and subject matter of the poem, the name of the king or chieftain to whom the poem relates and the occasion which called forth the eulogy are also found.