How old is the tradition of writing a Guru's biography, and which Marathi poets are mentioned as carrying on this practice?

According to Chapter 0, the service of writing a Guru's biography is not a recent development; it is described as being very ancient. To support this claim, the text points out that this practice is mentioned in the Narada Purana. The source then identifies two famous and world-renowned poets who continued this tradition in the Marathi language. The first is Maharaj Shri Mahipati, who wrote the biographies of saints in the Ovi meter in his works Shri Bhaktalilamrut and Shri Santalilamrut. The second is Shri Dasganu Maharaj, who similarly composed brief biographies of more recent Maharashtrian saints in the Ovi meter.