Final answer:
Santa Anna ordered the execution of Fanning and the other Texan prisoners to assert his authority and create fear among the rebels.
Step-by-step explanation:
Santa Anna ordered the execution of Fanning and the other Texan prisoners because he wanted to send a message and create fear among the Texan rebels. Executing the prisoners was a way for Santa Anna to assert his authority and deter any further resistance from the Texans.
This act was part of the larger context of the Texas Revolution, where the Texan settlers sought independence from Mexican rule. Santa Anna, as the Mexican president and military leader, saw the Texans as rebels and treated them harshly in order to suppress their uprising.
It is important to note that Santa Anna's decision to order the execution was a ruthless and controversial action that further fueled the Texan desire for independence.
Learn more about Santa Anna's execution of Texan prisoners