Rihannsu have great respect for names and words and believe that words help define a person, therefore all Rihannsu parents are very careful what they name their children using words like Galan, which means seeker, or Ael which means winged in the hopes that the name will help define who the child will be.
In recent years it has been verified that the Rihannsu are an offshoot of the Vulcan race. In the time of Surak when peace was coming to Vulcan some rejected that lifestyle and rather than tear the planet apart with rebellion and civil war they decided to leave and go somewhere else where they could be themselves without the teachings of Surak. Their leader was the former student of Surak, S'Task. He is known as the father of the Rihannsu.
Under the direction of S'Task ships were built to fly into space to find another home. A total of 80,000 men, women, and children left Vulcan. The fascinating story of their journey is documented in the books by Diane Duane one of which is entitled The Romulan Way. These people survived over 100 years in ships incapable of warp speed and eventually found their new home, actually a set of twin worlds: ch'Rihan - 'of the declared' which was the smaller of the two and was primary, and ch'Havran - 'of the travelers'. Eisn is the sun and also the name of the system.
Only 18,000 people survived the voyage. Most went down to the planets and settled but some refuesed to leave the ships. They stayed on the ships and maintained them for as long as possible until those on the planets all but forgot about the ship clans, or refused to waste resources on obsolete and dying ships. One by one they fell into decay and were lost.
Rihannsu history is rich and varied. They tried different forms of government settling on a representative form of government, a tricameron. The Praetorate and two branches of the Senate balance the power of each other. A Senator serves for life as representative of thier house.