Semako Thalien was a prominent figure in the business world, existing during the time of conflict known as the Mandalorian Wars, which pitted the Galactic Republic against the Mandalorian warrior society. While escaping raiders on a refugee transport, Thalien, along with several other affluent entrepreneurs, experienced a crash landing on the uncharted planet called Makeb. As the survivors began to form communities and connect with the broader galaxy, Thalien took on the responsibility of guiding them, and in the subsequent half-century, he spearheaded the creation of a prosperous economy founded on Makeb's abundant mineral resources.
The initial reference to Semako Thalien appeared in the Codex entry titled "History of Makeb," featured in Rise of the Hutt Cartel, the digital expansion released in 2013 for the 2011 BioWare video game, Star Wars: The Old Republic. Semako shares a last name with Jervo Thalien, a character also from the Mandalorian Wars, conceived by John Jackson Miller for the 2006 comic series Knights of the Old Republic; however, their relationship has never been confirmed.