 The Serbs gradually withdrew continuing fierce resistance hoping for Allies’ aid as British and French forces had landed in Salonika.The British were reluctant to send their troops into Serbia, but a French contingent of two divisions, commanded by General Maurice Sarrail, made a tentative advance up the Vardar Valley into Serbia, after being pushed back by the Bulgarian Second Army, the French were forced to pull back towards the Greek border, three British brigades came under increasingly heavy attacks and were forced back into Greece as well.The Bulgarian forces stopped at the border.