The creation of the T-103 lies in the T-002, which was destroyed by S.T.A.R.S. Alpha team in July 1998. The data acquired by Umbrella on Alpha team's reports proved that Tyrants of similar design could be used as adequate bio-weapons. With this data the T-103 was born.
During the Raccoon City Destruction Incident, a T-103 was dispatched to retrieve one of the last of the remaining G-virus samples; five others being transported by the same helicopter were used to stop a U.S. Special Forces incursion in the north of the city.
The T-103 model proved to Umbrella that the Tyrant class of B.O.Ws was commercially viable, in that they could be mass-produced, they were compliant with programming, and they were lethally effective at their tasks. As a result, not only were multiple batches of T-103 Tyrants produced, data from the T-103 was eventually used to enhance future forms of Tyrant. At least four models of Tyrant exist that can be directly connected to the T-103:
Nemesis-T Type: This "Pursuer" Tyrant was created by infesting a T-103 Tyrant with the Nemesis Parasite.
Tyrant R: This was a prototype of a newer, more advanced and even deadlier version of the T-103 model, though it was lost during the Raccoon City incident.
Ivan: This model of Tyrant was a T-103 variant specially modified to capitalise upon the human-like appearance of its previous model, enabling them to better blend into humanity whilst still being lethally effective bodyguards. Only 10 Ivan models are known to have ever been created, and at least two of these were assigned to Sergei Vladimir as his bodyguards; this first batch of Ivans were, in fact, created from clones of Sergei Vladimir.