 Greek and British Commonwealth troops fought back but were overwhelmed.On 20 April, after Greek resistance in the north had ceased, the Bulgarian Army entered Greek Thrace, without having fired a shot, with the goal of regaining its Aegean Sea outlet in Western Thrace and Eastern Macedonia.The Bulgarians occupied territory between the Strymon River and a line of demarcation running through Alexandroupoli and Svilengrad west of the Evros River.