Having lost her brother Rhaegar during Robert's Rebellion, her other brother Viserys to his own greed and her son to some unknown demon, Daenerys Targaryen truly believed she was the last of her name. After trekking up and down the Great Grass Sea and Bay of Dragons for six seasons, Dany finally returned to Westeros to claim the usurped land that's rightfully hers — until, that is, she discovers her new bedfellow (literally) is really her nephew who has more claim than she does. Yikes.
Game of Thrones hit us with the big reveal in the final moments of Season 7, when Bran watched Lyanna Stark and Rhaegar Targaryen tie the knot before giving birth to Jon "Aegon Targaryen" Snow. Season 8 will likely deal with the fallout of this tremendously awkward situation, but a quick history lesson reveals the loved-up couple have some further competition for the Iron Throne — a third Targaryen who has been hiding in plain site all along.
While this secret Targaryen is not as closely linked to the family as Jon and Dany are, he is very closely tied to the Baratheon clan, and as it turns out, the Targaryens as well. I am of course talking about Robert's bastard-born son, Gendry.
When we were first introduced to Gendry in Season 1, he was a lowly blacksmith in Flea Bottom, hidden away after Cersei's rampage to murder all threats to Joffrey's reign after Robert's death. Through his father, Gendry is Daenerys's second cousin once removed and Jon Snow's third cousin, although this may differ depending on whether you're taking the #TV show or books into account.
It's no secret that royal bloodlines are complicated and convoluted affairs, especially as the Great Houses of Westeros have been swapping partners for alliances for centuries, so it's small wonder all these connections are crawling out of the woodwork now. According to Game of Thrones lore (and this is where things get a little complicated) we can trace Gendry's Targaryen lineage back to Robert Baratheon's grandmother Rhaelle, who was a full-blooded Targaryen. Rhaelle was married to Ormund Baratheon, and their son Steffon was father to Renly, Stannis and Robert.
In 'A Song Of Ice And Fire', it's made clear that Robert's Targaryen connection is what gave him legitimacy to the throne after the Rebellion. Rhaelle, after all, was the Mad King's aunt so the Targaryen line only survived through her descendants.