There has been plenty of activity behind the scenes since Chennaiyin FC were crowned the new kings of the Hero Indian Super League (ISL) after beating FC Goa 3-2 on December 20 at the Jawaharlal Nehru Stadium in Fatorda. Several Hero I-League teams as well as clubs from other leagues have since secured the services of Hero ISL’s biggest stars.Defending I-League champions Mohun Bagan have been one of the most active clubs in the transfer market, having secured the signatures of Brandon Fernandes (Mumbai City FC), Luciano Sobrosa (FC Goa), Lenny Rodrigues (FC Pune City) and Pronoy Halder (FC Goa) – bolstering a squad that already has the likes of Jeje Lalpekhlua (Chennaiyin FC), Sony Norde (Mumbai City FC), Dhanachandra Singh (Chennaiyin FC), Raju Gaikwad (FC Goa), Kingshuk Debnath (Mumbai City FC), Singam Subash Singh (Mumbai City FC), Pritam Kotal (FC Pune City) and Balwant Singh (Chennaiyin FC).Their arch-rivals East Bengal have also strengthened their selection with the addition of top Hero ISL performers such as TP Rehenesh (NorthEast United FC), Sanju Pradhan (NorthEast United FC), Bikash Jairu (FC Pune City), Narayan Das (FC Goa) and Sehnaj Singh (Delhi Dynamos FC). Meanwhile, last year’s runners-up Bengaluru FC have taken on goalkeeper Amrinder Singh (Atlético de Kolkata), one of the finds of Hero ISL 2015.Mumbai FC have boosted their line-up by bringing in Nidhin Lal (Mumbai FC), Anas Edathodika (Delhi Dynamos FC), Jayesh Rane (Chennaiyin FC), Arata Izumi (Atlético de Kolkata) and Sushil Kumar Singh (Atlético de Kolkata) to their fold.Salgaocar FC have brought in Karanjit Singh (Chennaiyin FC), Seityasen Singh (NorthEast United FC), Reagan Singh (NorthEast United FC), Keenan Almeida (FC Goa), Gabriel Fernandes (Mumbai City FC), Manandeep Singh (Kerala Blasters FC), Jackichand Singh (FC Pune City) and Hero ISL’s youngest hat-trick hero Thongkhosiem Haokip (FC Goa).Newcomers DSK Shivajians have also made a few stellar buys in Subrata Paul (Mumbai City FC), Zakeer Mudampara (Chennaiyin FC) and Israil Gurung (FC Pune City). Goalkeeper Arindam Bhattacharya (FC Pune City) has been snapped up by Sporting Clube de Goa along with Denson Devadas (FC Goa) and Mehrajuddin Wadoo (Chennaiyin FC).Meanwhile, notable transfers to overseas clubs include Roger Johnson (FC Pune City) to Charlton Athletic (England), Darren O’Dea (Mumbai City FC) to Dundee (Scotland), Kalu Uche (FC Pune City) to Almeria (Spain) and Peter Ramage (Kerala Blasters FC) to Coventry City (England).The nine-team I-League commenced last week with Mohun Bagan, East Bengal and Bengaluru FC registering wins and Shillong Lajong sharing points with Mumbai FC following a goal-less draw.