The Prince of Tyre seems almost like a symbol in Ezekiel, but technically, he was a real guy. He's described as someone of goodness, justice, and wealth who manages to blow it all and break bad.
At first, he's the golden boy:
You were the signet of perfection, full of wisdom and perfect in beauty. You were in Eden, the garden of God; every precious stone was your covering, carnelian, chrysolite, and moonstone, beryl, onyx, and jasper, sapphire, turquoise, and emerald; and worked in gold were your settings and your engravings. (28:12-13)
But the Prince of Tyre turns greedy, oppressive, and wicked—and, above all, arrogant. That's his undoing. Like Adam falling from Eden, the "guardian cherub" who'd watched over the Prince of Tyre's perfect existence boots him out. He's a symbol of everyone who is undone by pride and corruption.