The captain, as his name indicates, is the head of Corona Royal Guard. As such, he spends a majority of his time working to ensure the safety within the kingdom remains intact.
At some point in time, the captain came to adopt an orphaned girl named Cassandra, whom he raised from childhood as his daughter.
The captain is gruff and no-nonsense, with a strict sense of order. He does not tolerate any criminals within the kingdom, and will go on an endless pursuit to apprehend those who offend Corona's crown. He tends to view criminals as worthless and pathetic, and understandably refuses to show even the slightest bit of sympathy or kindness toward them, as seen in his relationship with his arch-rival, Flynn Rider. Even after Eugene proved his selflessness by rescuing Corona's lost princess, Rapunzel, the captain refused to welcome him into the castle with open arms. Instead, he chose to ruin Eugene's life whenever the chance came his way, even if it meant going against common decency and fairness, showing a bitter and spiteful side to himself.
However, the captain is not as cruel as he may seem; he is able to show humility and admit when he may have overreacted, though he is a man who will stand by his decisions for the most part. He is also loving and protective toward his daughter, Cassandra. According to Cassandra, the captain raised her to be strong, independent, and taught her the importance of earning your keep through hard work. He also appears to have a soft spot for Maximus, whom he interacts with in an extremely friendly and jovial manner, a side of the captain that is practically never seen elsewhere. Maximus is also the only character that the captain appears to genuinely respect, outside the royal family.
The captain first appears after Flynn Rider and the Stabbington Brothers had robbed the castle of the lost princess's tiara. The chase leads the captain and his men into the forest, where Flynn manages to evade a majority of them. The captain and his faithful horse, Maximus, come close to apprehending the thief, only for the captain to be kicked off his horse, separating the two and allowing Flynn to escape. Meanwhile, the captain and his guards succeed in arresting the Stabbington Brothers.
Later on, the captain receives intel that Flynn is at the Snuggly Duckling. The guards raid the place, but are fooled by the local Pub Thugs into believing Flynn had never arrived. Maximus returns, however, and is able to sniff out a secret passage that was likely used by Flynn to escape. Fortunately for the guards, this turns out to be the case, as they soon encounter Flynn and his accomplice, Rapunzel. A chase into a canyon ensues, where the captain and his men are quickly defeated by Flynn. That leaves only Maximus to battle, but due to Rapunzel's interference, Flynn escapes once again. The captain and his crew regain consciousness, but before they can make another attempt, they are swept away by rushing waters released as a result of the broken dam.
The captain does not appear again until the final act of the movie, where Flynn has finally been arrested. Rider is sentenced to death, but on their way to the noose, the guards are taken out by the Pub Thugs in their effort to rescue Flynn. The captain is knocked out by Attila, thus allowing Flynn to escape. The captain is not seen again for the remainder of the film.
The captain plays a minor role in the sequel, taking place six months after the events of Tangled, and before Rapunzel and Eugene's wedding in Tangled: Before Ever After. He retains his position as captain of the guard, and is first seen chasing down Rapunzel and Flynn (now going by his true name, Eugene) as they pursue the kingdom's border wall to allow Rapunzel a chance to look out into the land surrounding Corona. The captain fails to stop them, once again, but simply accepts defeat and calls Rapunzel back once preparations for her coronation are set to begin.
Later on, the captain is seen ensuring King Frederic that Corona's security has been amped, per request, although this does not stop the pirate Lady Caine and her band of thieves from crashing Rapunzel's coronation. The thieves barricade the hall's door, locking the guards out, though they manage to break through in time to arrest the villains, who were already defeated by Rapunzel, Eugene and Cassandra.
The captain plays a supporting role in the animated series, which expands his character. Due to being considerably more pessimistic, jaded and down-to-earth than the other characters, the captain is often looked down upon as an antagonistic figure of sorts. Most significantly, however, his relationship with Cassandra is touched upon; the episode "Great Expotations" revealed that the captain has reservations about granting Cassandra a portion on the guard, despite believing her to be more than qualified for the job. She manages to prove her worth after assisting the young alchemist, Varian, in saving the castle, though she would continue to make efforts to highlight her capabilities. In "Under Raps", Cassandra lured a separatist into Corona to uncover the reasoning behind his fascination with an ancient journal that belonged to one of Corona's previous kings. As revealed to Rapunzel, part of her reason for doing so was to prove herself to her father.
In "Secret of the Sun Drop", King Frederic learns that Cassandra was responsible for getting Rapunzel across Corona's wall. As punishment, she is scheduled to be sent to a convent. The captain shows no anger toward Cassandra's actions—only deep remorse for not being able to speak against the king's decision. His inability to do so disappoints Cassandra, creating a brief rift between the two. Later on, the castle falls under attack by a young alchemist and his monster. During the battle, the captain is injured. Cassandra rushes to her father's side and expresses that she has never been disappointed in him, apologizing for her words from earlier and mending their rift. Due to his injuries, however, the captain is unable to lead an ordered assault against Varian. He instead finally embraces Cassandra's capabilities and appoints her as his replacement.
The rivalry between Eugene and the captain remains, despite Eugene being a much-beloved resident of the castle's household. Examples of this are seen in "Fitzherbert P.I.", where Eugene pursues a position in the royal guard, prompting the captain to sabotage Eugene's chances of earning the job, and "Big Brothers of Corona", where the captain was against the idea of hiring Eugene's former partner, Lance Strongbow, as a much-needed guard instructor. Despite his firm stance on situations, the captain has shown that his mind can be changed, and he will begrudgingly own up to his wrong doings, if any.
In a prologue in "Rapunzel's Return", on the night Rapunzel was kidnapped as a baby, the Captain and several Guards were in pursuit of Mother Gothel. The Captain located Gothel's cottage and young daughter, but Gothel managed to escape with the princess, but abandoned Cassandra. Following Gothel's escape, the Captain assured Cassandra she was safe with him and took her back to the Castle and adopted her, raising Cassandra as his own child. In the present day, King Frederic and Queen Arianna fell under the control of Varian, Andrew and the Separatists of Saporia, allowing them to take command of Corona. Following the events, The Captain conducted search parties to find and bring back Rapunzel and her friends to save the kingdom and is still currently away searching for them, unaware that Rapunzel and her friends learned the news and have recently returned.