Imperial Washington

Next stop, Union Station. Buses, cabs and a tourist-laden amphibious "duck" clutter the view of the architecture Murphy wants to discuss.

He's a reddish-haired man of 54 who gives no indication that the blue blazer and gray vest he's wearing might be at least one layer too many for a warm day. A longtime editor at the Atlantic Monthly who recently signed on with Vanity Fair, Murphy also worked in Washington for eight years, at the Wilson Quarterly, beginning in 1977.

He'd been through Union Station maybe 150 times, he says, but "never saw the obvious thing about it."

Which is?

"That it's a triple Roman triumphal arch in the front." And that, when you head inside, you'll enter a vast room with "vaulted ceilings taken from the Baths of Diocletian."

At the time of Union Station's construction in 1907, this historical allusion meant nothing more than that neoclassical architecture was still in vogue and that a gargantuan Roman bathhouse offered a useful model for a super-sized train station. But these days, when you think about who the emperor Diocletian was, the allusion gets more interesting.

He came to power in A.D. 284, after a long period of imperial decline. "Diocletian finally pulls the empire back together," Murphy says. But there's a downside: Diocletian's Rome "is largely a military state. Security becomes paramount."

Murphy opens his book with an imagined scene of Diocletian on the road. Advance men negotiate the emperor's security. Eagle-bearing legionaries follow to ensure it. Diplomats, adjutants and interpreters stay close at hand, along with "the core group of bureaucrats and toadies who function within any nimbus of great power."

Sound familiar?

As we'll see, it was a similar, modern-day vision that finally spurred Murphy to write his book. But he'd been fascinated by Rome long before that.

Murphy's father was an illustrator and cartoonist who drew, among other things, the long-running historical comic strip "Prince Valiant." (For a quarter of a century, beginning in 1979, the son wrote his father's scripts.) A cartoonist can work anywhere, and when the younger Murphy was 11, the family moved from Connecticut to Dublin. There he found himself in a school where studying Latin was taken for granted.

He loved it. A family trip to Rome cemented his interest.