(Rome (6th head) was destroyed in 64AD, resulting in its appearance in John's vision "as if it had been slain" in 95AD.
But, this 6th head "was healed" in the End Times & was restored as the 7th head.)
(Rev. 13: 1- 3) &
(Rev. 17: 9, 10)
Revelation 17: 9, 10: "Here is the mind that has wisdom. The 7 heads are 7 mountains on which the woman sits (Rome), and they (7
heads) are 7 kings; 5 have fallen, one is (6th head of John's time), the other (7th head) has not yet come; & when he comes, he must remain a little while."