With "Hell on Wheels" star Anson Mount having been cast as Black Bolt for the upcoming "Inhumans" television series, this is a perfect opportunity to explore the comic book history of the most famous member of the Inhumans Royal Family, the longtime king of the Inhumans.
The Inhuman known as Black Bolt (whose "real" name is the too-perfect-to-believe Blackagar Boltagon) is one of the most powerful beings on Earth, but much of his power comes from the hypersonic qualities of his voice. Therefore, since even a whisper from Black Bolt could be deadly, he almost always remains silent. Due to this silence, he is difficult for people to understand, but even beyond his reluctance to speak, Black Bolt is one of the most fascinatingly inscrutable comic book characters that Jack Kirby and Stan Lee ever created.
When we first met Black Bolt in "Fantastic Four" #45 (by Jack Kirby, Stan Lee and Joe Sinnott), all we knew was that he was very powerful.
We soon learned that he was the deposed ruler of the mysterious race of super-beings known as the Inhumans. Black Bolt's exile did not last long, as by "Fantastic Four" #47, he was already back in control of his people, rocking one of those amazing crowns that only Jack Kirby could envision.
In the Jack Kirby/Stan Lee heyday of the Marvel Universe, there were five prominent monarchs in the Marvel Universe: Odin, Namor, Doctor Doom, Black Bolt and Black Panther. A recurring theme between those five is the notion that being in charge of a group of people causes you to sometimes do things that you wouldn't be proud of otherwise, but you feel that you have to to protect your people. This was clear in the very first "Inhumans" feature in the pages of "Amazing Adventures" (where Jack Kirby was given the chance to write and draw a comic for Marvel by himself - he had already committed to leaving Marvel for DC at this point, though), where Black Bolt's mysterious ways drew questions from his royal cousins, who took issue with the way that Black Bolt made decisions without consulting anyone.
While Black Bolt is clearly a good man, that way of ruling has always been the way that he has handled things. He has always been a "it's my way or the high way" type of leader, which is especially interesting when you realize just how empathetic a person he is at his heart. However, he has a very specific view of how a leader should handle things and over the years it has caused a lot of stress due to how disconnected he can be from his people (even his closest allies).
Black Bolt's sensitive nature has been most explicit when it comes to his brother, Maximus, and to his queen, Medusa. Despite Maximus' many attempts to take over the Inhumans, Black Bolt just cannot bring himself to get rid of his brother, especially since he blames himself for Maximus' madness, as it appears to be in part a side effect of the first usage of Black Bolt's powers (that same first usage also accidentally caused a building to collapse and kill both of their parents). As for Medusa, Black Bolt had been in love for her for years and often his feelings for her that best serve to keep him at least somewhat grounded (the two married after a surprisingly long courtship and later had a son together named Ahura).
One of the areas where Black Bolt's secrecy was of the greatest importance was when he joined the secretive group of superheroes known as the Illuminati. the leaders of the various sections of the Marvel superhero world. Behind the scenes, these heroes (including Iron Man, Mister Fantastic, Professor X and Doctor Strange) helped to greatly influence the events of the Marvel Universe.
Over the years, the guiding principle that Black Bolt maintained with the Inhumans was basically isolationism. The Inhuman city of Attilan was initially hidden in different places on Earth before ultimately moving to the moon. That is how dedicated Black Bolt was to keeping his people out of conflict with the rest of the world. He maintained that stance during the superhero Civil War, but then dealt with a major blow to the freedom of his people when his former brother-in-law, Quicksilver, stole the Terrigen crystals that gave new Inhumans their abilities. Black Bolt eventually had to take on the entire United States military to get the crystals back, but while he was busy with that mission, his brother Maximus once again took control of the Inhumans from him.
Black Bolt took over again just in time for one of his decisions as part of the Illuminati came home to roost, as the Illuminati had attempted to send the Hulk to a peaceful planet to keep him from doing more destructive rampages on Earth. The rocket they used accidentally landed on a gladiator planet instead. The rocket then exploded after the Hulk had conquered the planet, killing the Hulk's new wife. The Hulk headed back to Earth for revenge. He savagely beat Black Bolt. Soon after, though, we learned that the Black Bolt he had defeated was actually a Skrull and that the Skrulls had Black Bolt as their prisoner.
Once he was freed, Black Bolt changed his stance on isolationism and led his Inhumans brethren to a takeover of the Kree. This led to a conflict with the Shi'ar, who had recently been conquered themselves by the Earth villain, Vulcan. In the end, Black Bolt managed to stop Vulcan, but seemingly at the cost of both of their lives. Black Bolt was made out of sterner things than that, though, and he managed to survive and return to his people, who ultimately decided to give up their rule over the Kree.
During the "Infinity" crossover, Thanos tried to take control of the Terrigen Mists (as part of a plot to find his own half-Inhuman son). Once again making a decision on his own that greatly affected his people, Black Bolt determined that he was going to stop Thanos even if it meant destroying the Terrigen crystals himself. So (with help from his brother, Maximus), Black Bolt created a Terrigen Bomb.
He then detonated it, sending the mists all over the globe. This triggered Inhuman evolutions in any human on Earth who had some sort of Inhuman ancestry (most of whom had no idea that ever had any such ancestry, since the Inhumans go back millennia). This last action was finally the straw that broke the camel's back, and Black Bolt was no longer the head of the Inhumans and he split with his wife, Medusa.
Since his departure as leader of the Inhumans, Black Bolt has been maintaining the Quiet Room, a place where superpowered beings can come to find common ground. It's a truly neutral place.
However, recently, after Emma Frost made the world believe that Black Bolt had killed Cyclops of the X-Men, Black Bolt is now a target of the X-Men in the current "Inhumans vs. X-Men" event.
Black Bolt's mysterious and often disconnected way of handling his rule of the Inhumans should translate very well to a dramatic television series, where there's a long history of headstrong leaders making rash decisions and then having his underlings have to deal with the mess that he causes.