The Romulan Exodus from Vulcan

When Surak's philosophy of logic spread across Vulcan, part of the population refused to give up its emotions. Described in Vulcan tradition as those who "marched beneath the raptor's wings", these dissidents left their homeworld in the same era and travelled far across space before settling the twin worlds of Romulus and Remus.

Over the centuries the two branches grew apart. The Romulans built an expansionist, secretive empire, and their shared ancestry with the Vulcans was largely forgotten by outsiders. In 2266 Starfleet officers saw a Romulan face for the first time and were stunned by the resemblance to Spock.

The split shaped Vulcan-Romulan relations for good. In 2368 Spock travelled in secret to Romulus to support an underground movement favouring reunification, a cause that failed in the short term. Only in the 32nd century, after the destruction of Romulus and the later upheavals, did the two peoples come together again on Vulcan, renamed Ni'Var, a reunion that drew on Spock's legacy.