The invasion of Jerusalem by Shishak, king of Egypt, was driven by his awareness of the vast treasures stored within the city. Knowing the immense wealth amassed there, he assumed King Rehoboam would be powerless to stop him [ביאור שטיינזלץ]. Rehoboam had placed his trust and security in the great fortune inherited from his father, Solomon. Consequently, his specific punishment was the loss of that very wealth at the hands of the Egyptian king [אברבנאל].
The invading forces looted the treasuries of both God's temple and the royal palace. These storehouses contained massive quantities of riches that had been gathering since the days of David and had reached extraordinary levels during Solomon's reign [ביאור שטיינזלץ]. The invaders took absolutely everything. This total devastation is understood either as a complete emptying of the treasuries, leaving nothing behind [מצודת דוד], or as a reference to the loss of a specific, highly prized object: King Solomon's throne, which was considered the most beloved and significant of all the royal treasures [רש״י].
Among the looted items were the gold shields. During Solomon's era, gold was so plentiful that he even used it to plate the shields of his royal guard [ביאור שטיינזלץ]. However, other famous gold artifacts from Solomon's time, such as the three hundred large shields and the golden drinking vessels, were notably absent from the spoils. These specific items were not taken by Shishak because they had already been scattered and lost during Solomon's later years, even though a substantial amount of the kingdom's wealth had managed to survive into Rehoboam's reign [אברבנאל].