There are many synonyms for the phrase "call to battle," depending on the context and tone required. Some synonyms could be "rally cry," "war cry," "charge," "summon to arms," "toll the trumpet," "muster," or "sound the alarm." Depending on the situation, other synonyms could include "mobilize," "rouse," "incite," "bring to action," "galvanize," or "inspire to fight." These synonyms all connote an urgent and forceful command to action, either in a physical or metaphorical sense. Whatever the choice of synonym, the phrase "call to battle" evokes a sense of urgency and necessity, compelling individuals to act quickly and decisively.