I have an idea for a wizard affiliated with the Zhentarim and need help with his background. 

The character was orphaned at a young age.  Based on his prodigious ability, he was recruited into a notable wizard academy for training.  He subsequently came to the attention of a Zhentarim representative and was recruited into the Black Network to serve as an arcane hitman.  I am having trouble making connections between the wizard academy and introduction into the Zhentarim.  What wizard school would have taken the character in?  Who might his mentor have been?  Who from the Zhentarim may have recruited him into the Black Network?  It is conceivable that the character could have been a Zhent from the beginning.  For example, the character's parents could have been powerful wizards affiliated with the Zhentarim who were eliminated by the Harpers.  A powerful mage within the network could have directed the character's life from that point onward.

I have seen a lot of conflicting information on Fandom sites as well as in a "Secrets of the Zhentarim" guide on which Ed Greenwood consulted.  I am unsure what represents current canon and would appreciate any suggestions others can provide.  Thanks in advance.

What time period is the game being played in? The Zhentarim of the late 1300 DR is a very different organization from that of the late 1400’s. 

Good point.  We are playing Tyranny of Dragons.  Online info says "Tyranny of Dragons began roughly in Tarsakh, 1373 DR, using the Timeline of the shared world state."

So at hat time the Zhentarim are actually cleric driven with Banite and Cyricist factions and then Manshoon and the wizards almost a third faction. The timing is also around the time of the manshoon clone war. The real problem is that there are no real Wizard academies in the area or pretty much anywhere in Faerun. It is more likely that a Zhentil Wizard took him on as a servant/slave then discovered his talent and converted him to be an apprentice and underling in the organization. If your starting at L1 the Zhentil Wizard might not be more than L5 initially. Or maybe you showed some signs of skill before your parents died and he wanted to make use of you - he might even actually be the one that killed your parents (or arranged it) in order to get control - Zhentil aren’t known for being nice guys.

Thanks.  You've clarified things for me a bit.  Based on some (much) further reading, I believe the following could work:

I think it would be safe to say that the character was born in the mid-to-late 1340s.  This means he would have started his wizard training in the mid-1350s and been a young adult (early 20s) by the time Bane resurrected and everything changed.  This means he could have been brought into the Zhentarim by Sememmon, or even Manshoon, and trained under Thagdal or another wizard in the Tower of the Art in Zhentil Keep.  I envision he would have left to become an adventurer at age 25 or shortly thereafter, which would be before the Keep was destroyed in 1383, if I am not mistaken.  Alternately, he could train under Sememmon or Ashemmi in Darkhold, but that would be more like an apprenticeship (no group of wizards or guild in Darkhold as far as I read).  It would also be a bit more complicated since Ashemmi's underwent a personality change in the mid-1350s.

What do you think?

Rats... Just realized I was wrong.  ToD starts in 1489.

Yeah it’s after the spell plague officially but like most modules with a little tinkering it can go at almost any time. What you had was good but realize that as you approach the spellplague Somme on and Ashe I leave the zhentarim and take up with Khelbin Blackstaff.
That said the late 1400’s zhentarim are less a  criminal organization and more a mercenary one. Manshoon is still around as a faction leader along with the perighost in Darkhold and religious factions around the Moonsea. As ToD takes place near Darkhold the easiest way is to just be hired on as a low level mercenary mage and then be sent out by the on a mission - maybe as a courier and then you get caught up in the events and become the Zhentarim’s lead figure in the story.

So complicated!  I never realized how unstable things became in the Zhentarim.  Then again, my remembrances of the organization are based on the 1980s to early 1990s (up to Time of Troubles).  Based on information I could glean online, it looks to me like the Tower of the Art was only around between 1368-1383, which is not really enough time to support the character's development.  

The character is going to be a reborn (per VRGtR), so I think I can still make something work that would involve the major Zhent players during the height of their power.  The character was born in 1340 DR, the Year of the Lion, to notable wizards who were affiliated with the Zhentarim and allies of Manshoon.  In 1346, the character's parents were targeted for assassination by the Harpers.  Recognizing the character's prodigious talent, Manshoon apprenticed the young boy.  The character studied under Manshoon for a number of years, learning everything he could about wizardry.  In 1352, Manshoon sent the character to Darkhold to serve under Sememmon and begin engaging in missions for the Zhentarim.  During this time, the character continued his studies under Sememmon as well as learning the arts of subterfuge and assassination from The Three.  In 1364, the character left Darkhold with a party of Zhentarim agents to search for an artifact reputed to provide immortality.  After locating the artifact and defeating its guardians, the character activated it and became a reborn.  In the process, the character lost his mind.  He killed the remaining members of his party and subsequently spent more than a century wandering aimlessly.  In the late 15th century, the character regained his memories.  He returned to Darkhold and reestablished his affiliation with the Zhentarim.  Near the start of ToD, the Zhentarim tasked the character to investigate the cultists' activities.  

My problem with that (and a lot of convoluted backstories I hear here is that these are typically L1 characters. Given the back story the character should be anywhere from L10 to L18 not L1.  Try Manshoon is out searching for a relic that grants immortality  that is supposed to be held by a Harper agent. When he arrives he finds the place shattered by a recent combat, the artifact is gone but a young man/woman (your character) is recovering as a reborn. Under questioning by Manshoon he tells the story of the family being attacked by red wizards looking for the artifact and his parents fighting them to the death. Near the end he took the artifact at his parents direction just before they were killed and accidentally attuned to it causing it to explode killing everyone (red wizards, his parents, and himself) but then raising him as a reborn. He proves to have some basic magical training already from his parents and Manshoon offers him a chance at revenge by joining his faction of the Zhentarim and becoming an apprentice. He agrees and after further training by Manshoon is sent out on his first mission and becomes involved in ToD.

The great thing about the Zhentarim is that individual cells of the organization can be wildly different from other cells…an organization operating in one city might be a ruthless mercenary company…while another operating in a separate city might be smugglers, who prefer to do things non-violently.

Some Zhentarim cells might have no idea that their organization is, on a grand scale, run by villains.

Except for maybe the leader of the cell; who in your case might be the one to take the mage under their wing.

Otherwise, small groups of Zhentarim essentially just treat each other as a tight-knit family, who really just operate by mafia rules.

As for what wizard subclass to go with a Zhentarim agent…a Bladesinger, War Mage, or Evocation Wizard would fit with a Zhentarim mercenary company, since they would value the artillery a blasting wizard would provide.

For a more sneaky Zhentarim cell…you can’t go wrong with an Illusion Wizard, or even Divination Wizard…that last one would be great in theory: if they need to run an operation successfully, they lean on the Wizard’s Portents at critical moments.

The wizard could become the Zhentarim cell’s lucky charm.

Quote from Wi1dBi11>>

My problem with that (and a lot of convoluted backstories I hear here is that these are typically L1 characters. Given the back story the character should be anywhere from L10 to L18 not L1.  Try Manshoon is out searching for a relic that grants immortality  that is supposed to be held by a Harper agent. When he arrives he finds the place shattered by a recent combat, the artifact is gone but a young man/woman (your character) is recovering as a reborn. Under questioning by Manshoon he tells the story of the family being attacked by red wizards looking for the artifact and his parents fighting them to the death. Near the end he took the artifact at his parents direction just before they were killed and accidentally attuned to it causing it to explode killing everyone (red wizards, his parents, and himself) but then raising him as a reborn. He proves to have some basic magical training already from his parents and Manshoon offers him a chance at revenge by joining his faction of the Zhentarim and becoming an apprentice. He agrees and after further training by Manshoon is sent out on his first mission and becomes involved in ToD.

Can't "this" enough, at least the first few sentences.  Faction affiliation is a cool thing to have, and faction agent is a cool background, though some DMs don't grant it from the getgo because Lvl 1s are basically nobodies (especially to some of the high flying ground like The Black Network) and players of starting characters need to recognize that scope.  There's a cool pay what you can product on DMsGuild, prepared by a DDB member I believe, Guide to the Five Factions, that includes a handy one page "letter of introduction" to a PCs respective faction and puts their role in that faction into perspective.  There's also, IIRC, a neat little system, that even if not mechanically imnplemented by your DM gives a player of a character at a particular level an idea what to expect their role and resources within a faction are supposed to have.  Most factions, especially the Zhentarim, aren't anarchist collectives and have chains of command protocols and standing rides on reknown within the organization.  Think Finn claiming he's "a big deal in the Resistance" and remember the look Han Solo, who knows a thing or two about paramilitary and covert organizations, gives him.  Don't give yourself the nickname Big Deal.  For newcomers to a group like the Black Network, the same thing folks are told starting out in the military or other large orgs rings true, keep your head down (and be a sponge, learn all you can so you can meet any opportunity you're offered with knowledge).

The Zhentarim are basically the Mafia of Faerun.  Aside from occasional sanctioned mercenary (and even assassination work), they're a criminal enterprise ... and like a lot of large scale criminal organizations they embed themselves into their geographies infrastructure to further their ends, in the Z's case the trade system.  Just like in the "legitimate" world, there's a lot of uses for magic in criminality.  At level one, such a PC would just be someone called upon to perform "favors," as the Godfather would say, that work being tests of reliability and loyalty and ability to keep one's mouth shut.  As trust builds, the PC will be able to get more work with the organization as their reputation develops as a "goodfella".  In that capacity if the fortune of the character gives them the opportunity to be a true rainmaker for the organization, you're "made."

For level 1 characters joining secret societies, I often use this video for reference (and it's got so much in it to mine for DMs who want to give PCs a sense of scale to the bigger world they're engaging, look at Brando's general aloofness toward Sheen's character, and when he does become focused on their interaction, just how belittling he is):

A level one Faction Agent needs to be aware of that errand boy mindset, especially in a story like Tyranny of Dragons where some big parts start coming into play (and errand boy is almost always a better place to start at in a level campaign as opposed to "someone of consequence" as it gives you room to learn the world and choose your path).  Your job, in game as a level one PC with a faction agent background, and as a player creating a backstory, is simple.  There's enough story moving around in ToD that an effort to assert or triangulate a position within something like Zhentarum is likely going to be swept aside by the course of the adventure.  So what was it for?  Instead of killing you, the Zhentarum spared your life as a recent orphan (to a family targetted by the Z) or a urchin who got wise to them, or maybe you were enslaved by them and your talents uplifted you from that life.  Your arcane aptitude was discovered so their Wizard assets have over time taught you some of the basics while you engaged in petty crime in Z's interest.  You're an adventurer now, but when the Z comes calling for you, you know to answer to them.  Whether you wear the serpent tattoo or know some cant like gesture to signal your affiliation is up to you and the DM.

Thanks all for the feedback.  To clarify, I am  joining an ongoing game and am starting at level 5.  The DM is fine with my being a Zhent.  There is actually another party member who is also a Zhent (and quite a bit darker than me...).  My reasoning for the character seeking and using a magical device to become a reborn is that he experienced a tragedy as a child that left him emotionally scarred and seeking some kind of permanence.  He was also a young adult at the time of the transformation, so the recommendation from Wi1dBi11 couldn't work without some tweaking.  In some ways the story I provided earlier emulates that of Raistlin Majere, and I believe Raistlin was 3rd level at the time he completed his test in the Tower of High Sorcery.  Additionally, I feel that the Zhentarim was at its prime in the 14th century.  The current organization is not nearly as mage-centric, and depending on the year and source, it is unclear to me how much the last Manshoon standing continues to be part of the organization.