Prasthana Trayi

Haridas:

Prasthanatrayi, refers to the three texts of Hindu philosophy, especially the Vedanta schools. It consists of:

The Upanishads, known as Upadesha prasthana (injunctive texts)
The Brahma Sutras, known as Nyaya prasthana (logical text)
The Bhagavad Gita, known as Sadhana prasthana (practical text)

All the founders of the major schools of Vedanta, Adi Shankara, Ramanujacharya, Nimbarkacharya and Madhva wrote bhasyas (commentaries) on these texts.

Anyone proposing any philosophy in hinduism has to write commentaries on these three texts called as prasthana trayi.

Brahma sutras are also known as vedanta sutras. vedanta sutras were written by Badarayana Srila Veda Vyasa.

Pawan Sharma:

Noone wrote the Bhashyas on Prasthan Trayi after Vallabhacharya, until Jagadguru Rambhadracharya.

For the last 500 years (after Vallabhacharyaji), noone wrote Bhashyas in Sanskrit. Now Jagadguru Rambhadracharya (the present head of Ramanand sect) has written.

In fact, the title "Jagadguru" is traditionally given only to those who compose Sanskrit commentaries on the Prasthan Trayi. But nowadays, others also use it.