Simplify the following text for a Grade 5 native English-speaking person.
Original: Moreover , the road was blocked by a trench , and , towards the forest , an earthen wall had been built along the roadside , permitting the Germanic tribesmen to attack the Romans from cover .
Simplified: The road was blocked by a trench , and , towards the forest , an earthen wall had been built along the roadside . This let the tribesmen to attack the Romans from cover .