Short answers, pulled from the story.
Jataka tales are voluminous narratives about the previous lives of Gautama Buddha. The earliest known depictions appear on railings of an Indian stupa from the second century before the common era.
Scholars date the verse portions of these tales to the fifth century BCE while later prose parts were added up to the third century CE. These texts were originally transmitted in Prakrit languages and various forms of Sanskrit before spreading to Central Asian dialects like Khotanese and Tocharian.
The largest known collection is the Jātakatthavaññanā of the Theravada school included in the Khuddaka Nikaya of the Pali Canon. This text contains 547 poems arranged roughly by increasing number of verses with commentary providing context for the stanzas.
Illustrations found on the Bharhut stupa railing date from the late second to first century BCE alongside inscriptions marking early Jātaka art. Similar tales appear in murals at Ajanta caves and Silk Road sites like Kucha during the pre-Tang period between 421, 640 CE.
Chinese pilgrim Yijing visiting India in the seventh century recorded that jātaka plays were performed throughout five countries of ancient India. Chinese pilgrims Xuanzang and Faxian reported locations associated with these stories including four great stupas where Buddha ransomed doves gave away eyes heads bodies.