Flags were frequently used as rallying elements in the course of battles; infantrymen would collect round their colors for morale

https://zionscfs876.pinehavenscope.com/posts/reenacting-history-the-importance-of-accurate-civil-war-flags-2

Flags have been many times used as rallying elements in the time of battles; soldiers might gather round their colors for morale reinforce whilst faced with overwhelming odds.