I am the Alpha and the Omega, says the LORD GOD, who is, and who was, and who is to come, the Almighty. - Revelation 1: 8.
[Roman Emperor Domitian] began a letter, which his agents were to circulate, with the words: “Our LORD and GOD instructs you to do this!” and “LORD and GOD” became his regular title both in writing and conversation. - Chapter 12: Domitian, Section 13, The Twelve Casesars by Suetonius
Domitian was the first Flavian to be referred to as Caesar by the troops loyal to the family during the time between Otha’s execution and his father’s arrival in Rome to officially take the title.
On Domitian’s accession, he boasted to the Senate of having himself conferred the imperial power on Vespasian and Titus--it had now merely returned to him. This, in effect, makes him Alpha and Omega, First and Last.