(CNN) The roots of the current Golden Age of Television run deep, but its seeds can be traced to a pair of HBO dramas that left their mark in the 2000s, for shared reasons as well as two very different ones: "The Sopranos," because the series turned into an enormous mass-appeal hit; and "The Wire," because it never did.

Both shows feature huge ensemble casts, complex storylines and crime components -- the first (which actually premiered in 1999, but built in popularity as it ran through 2007) dealing with a mobster and his extended family; the latter (which made its debut in 2002) with the cops, drug dealers and other decaying institutions that occupy Baltimore's mean streets.

Both rank, rightfully, near the top of any discussion about the best TV shows ever, with Rolling Stone rating them 1-2 in a 2016 list of TV's top 100.

Yet beyond those creative credentials, each show emboldened and motivated others to forge ahead with original programming. While "The Sopranos" helped eradicate lines between premium and broadcast TV in terms of defining the outlines of a hit, "The Wire" demonstrated that a program boasting a small but insanely loyal audience, and the critical adulation that goes with it, was validation enough to keep it going.

Indeed, in today's splintered landscape, the legacy of "The Wire" might be even more resonant -- the idea of using a series as a larger brand-building ambassador. Based on that amorphous formula, a show can yield ancillary benefits -- starting with the overall image of the network or service carrying it -- that go well beyond the nuts and bolts of ratings.

As "The Wire" creator David Simon told Rolling Stone for that aforementioned list, "After the first season, I thought, 'There's no way I'm being renewed.' But no one has told us to stop. I mean, any schmuck making over 50 hours of TV on what ails the American city and expecting people to watch it deserves what he gets."

The latitude to produce shows with that kind of creative ambition, unfettered by the ratings demands traditionally associated with television, has played a key role in allowing writer-producers to unleash their best work. Although some of those programs have become hits, others were allowed to run out their course, narrowly playing to the TV equivalent of off-Broadway crowds.

These weren't the first programs to meet these descriptions, but none have been more significant or emblematic in laying the groundwork that has allowed such premium fare to flourish.

"The Sopranos" clearly emboldened basic cable networks to more ambitiously pursue original production, yielding a series of network-defining shows: FX's "The Shield" and "Nip/Tuck" in 2002 and 2003, respectively; AMC's "Mad Men" and "Breaking Bad" in 2007 and 2008; and Netflix's "House of Cards" and "Orange is the New Black" in 2013, which elevated streaming to a new level.

'The Sopranos'

The program's success also forced the broadcast networks to contemplate what that meant for them. Famously, that included then-NBC CEO Robert Wright circulating an especially violent episode of "The Sopranos" to top Hollywood executives in 2001, along with a letter asking what to make of the show's popularity when his network couldn't air something that explicit.

Wright wanted feedback, he wrote, about "how [the show] impacts mainstream entertainment," an issue that he said required "serious thought." The query followed a Newsweek cover story suggesting that "The Sopranos" "has the rest of TV running for its life."

Broadcasters did respond with more intricate programs of their own in the 2000s, perhaps most notably ABC's "Lost," which set a precedent by announcing an end date far in advance, then crafting a finale that gradually built (disappointingly, as it turned out) toward a conclusion.

Where HBO once had the premium playing field largely to itself, "The Sopranos" and "The Wire" have ensured that the pay service (like CNN, a division of WarnerMedia) now has plenty of competition and company.

While that dynamic presents challenges for HBO, it has benefited discriminating viewers by raising the bar for what's come to be known as peak TV, where the number of shows aspiring to such lofty standards has grown from a dribble to another kind of mob.