Dating bhagavad gita
Scholars accept dates from the fifth century to the second century BCE as the probable range.
Professor Jeaneane Fowler, in her commentary on the Gita, considers second century BCE to be the likely date of composition.
So, there is doubt about whether the Bhagavad Gita was widely known about during the lifetime of Gautama Buddha.
The smriti texts of the period between 200 BCE - 100 CE belong to the emerging "Hindu Synthesis", proclaiming the authority of the Vedas while integrating various Indian traditions and religions.
The Bhagavad Gitas call for selfless action inspired many leaders of the Indian independence movement including Bal Gangadhar Tilak and Mohandas Karamchand Gandhi.
The emerging self-definitions of Hinduism were forged in the context of continuous interaction with heterodox religions (Buddhists, Jains, Ajivikas) throughout this whole period, and with foreign people (Yavanas, or Greeks; Sakas, or Scythians; Pahlavas, or Parthians; and Kusanas, or Kushans) from the third phase on [between the Mauryan empire and the rise of the Guptas].