Unlike the Marvel Universe, the DC Universe consists of many different ones often siloed off from each other. Characters like Sandman exist in the broader DC Comics universe, but rarely interact, Constantine travels easily between all these worlds, making him an ideal character for interpretation and a perfect vehicle to explore DC's rich history and lore.

Modeled On Sting

Artists and Constantine co-creators Stephen Bissette and John Totleben modeled the character on Sting, the frontman for The Police. Little doubt exists about the likeness, especially in his first appearance in Swamp Thing #37 from 1985, drawn by Rick Veitch. The close resemblance remained a factor for years, though the character later evolved with other artists.

Sting acknowledged the artistic tribute and paid tribute himself to Constantine during the character's thirtieth anniversary, with the musician contributing a forward to a collected edition and making a video where he dressed up as the character.

Supernatural Advisor

Constantine's initial function in Swamp Thing serves as a supernatural advisor. At this point, Swamp Thing still explores his power and identity after learning that he isn't Alec Holland transformed into a plant creature but a plant creature with Holland's memories. He plays an integral role in a key sequence from arguably some of the best comic books ever, by Alan Moore, Bissette, Veitch, and Totleben.

Constantine also helps Swamp Thing better understand his extraordinary powers which derive from The Green, a cosmic energy force that also fuels Poison Ivy in more recent comics.

Powerful Sorcerer

Constantine ranks among the most powerful magical beings in the DC Universe and comic book fans may argue he's the most powerful. His existence hinges entirely on the fact he tricked demons, including the powerful First, several times in order to first spare the soul of a dying friend and then his when he contracted cancer.

Constantine possesses unparalleled knowledge of sorcery and divination, giving him access to ancient and powerful magic he uses to help others against supernatural threats.

Crisis On Infinite Earths

Constantine evidences his incredible magical perception by being among the few beings in the DC Universe with the memory of Crisis On Infinite Earths. This 1985 epic, among the best DC Comics crossover events ever, consolidated the sprawling DC multiverse into one single continuity that erased decades of comic book storylines.

He also maintains awareness of subsequent DC reboots, including ones that substantially altered his origins and powers, like New 52, Rebirth, and others that routinely update continuity in the comics.

Meeting The Sandman

DC Comics fans know Constantine's first meeting with The Sandman plays out pretty much the same as it does in the new Netflix series, with a few major exceptions. Constantine appears in The Sandman #3, linking the broader supernatural universe in DC Comics when Morpheus comes to him seeking his missing pouch of sand.

Constantine would go on to play a significant role in the broader Sandman universe, with his most important contribution arguably being the fact he serves as a link between the increasingly insulated Sandman mythos and the broader DC superhero realm.

Johanna Constantine

The Sandman replaces John Constantine with Johanna in the Netflix series adapting his first encounter with Dream, but DC fans know Johanna hails from the comics as well. She first appears in The Sandman #29 when Dream asks her to retrieve the head of his son, Orpheus, something the daring Johanna is uniquely suited for.

The Johanna character in the Netflix series pays homage to both versions from the comics, blending their disparate identities together in a surprising way that creates something new.

Astra Logue

DC Comics fans likely found the character of Astra familiar in The Sandman. Astra Logue played a key role in some of the best Hellblazer comic book issues, first appearing in full in issue #11. She summoned a demon to kill her abusive father, but the demon refused to leave her alone, leading to Constantine's intervention.

The Astra from the new Netflix series shares some similarities with the comic book one, though like Constantine, she's not the only version of Astra in live-action. Another adult version appeared in the Arrowverse, appearing in both Constantine and Legends of Tomorrow.

Aging Gracefully

Constantine ages normally in the comics, or at least he did prior to the substantive reboot during The New 52. Unlike most comic book characters whose age remains nebulous to allow them to maintain a necessary status quo for readers Constantine aged from his 30s to his 60s, celebrating birthdays annually from his debut in 1985 until the early 2000s.

He still ages, but now different versions exist in the DC multiverse thanks to different reboots. The Vertigo universe, or the original Constantine, presumably continues to age in real-time. However, his current DC Universe counterpart appears much younger and remains much more static in his youth.

Justice League Dark

Justice League Dark represents arguably Constantine's biggest role in the DC Universe in modern comics. He ed the team in 2011, taking his place alongside several other prominent DC magical characters like Zatanna and Doctor Fate, fighting against supernatural threats big and small. The team first forms after The Enchantress defeats the primary Justice League, requiring more supernaturally inclined heroes to take up the first.

Constantine continues to play a role on the team within recent comics and also factors heavily into their appearances in animation. He likely does when the rumored Justice League Dark live-action series manifests, though its fate remains uncertain after the Warner Bros. Discovery merger. Who plays Constantine in the show also remains a question. Matt Ryan, who has played the character on various shows including Legends of Tomorrow, may not reprise his role though he does voice the character in Harley Quinn.