Sridhara Svami is accepted as the original commentator on the Srimad-Bhagavatam. Perhaps you know that there is an edition of the Srimad-Bhagavatam by Krsna Sankara Sastri "abhinavah sukah'' Vedantacarya, Sahitya-tirtha, sribhagavatasudhanidhi, from Ahmedabad. In his book he has given almost all the important commentaries on the Bhagavatam, as follows: 1. Sridhara Svami 2. Sri Vamsidhara 3. Sri Gangasahaya 4. Srimad Viraraghavacarya 5. Srimad Vijayadhvaja Tirtha 6. Srimad Jiva Gosvami 7. Srimad Visvanatha Cakravarti Thakura 8. Srimad sukadeva 9. Gosvami Sri-giridharalal (Vallabhacarya Sampradaya) 10. Sri Bhagavat-prasadacarya, etc. Among all commentaries, Sridhara Svami's is given the first position. This parampara has existed for a very long time.
Letter to Sumati Morarji, 7 August, 1976