Sapien Sunrise is an extremist xenophobic rebel organization stationed in the Outer Colonies that believe alien integration in human colonies is destroying civilization. By 2558 Sapien Sunrise had started to use terrorist tactics using newly-acquired military hardware.
In 2558, after years of diplomatic work for peace between the Unified Earth Government and the Sangheili on Biko, UEG ambassador Richard Sekibo scheduled a peace conference between the two groups. This went against everything Sapien Sunrise stood for and Sekibo quickly became a target for them. Sapien Sunrise loudly threatened the embassy for months until Sekibo detected a serious security threat a week before the conference was scheduled to take place and petitioned the UEG for support, to which they declined. Sekibo went along with the peace talks anyway.
Sapien Sunrise had infiltrated the peace talks with four of their operatives disguising as civilians, four others disguised as embassy guards, and one disguised as Sekibo's own personal bodyguard. Their plan was to assassinate both the UEG and Sangheili ambassadors and blame it on the Sangheili. Their plan fell apart when SPARTAN-II John-117 infiltrated the embassy and killed the Sapien Sunrise operatives, escaping with Sekibo and a few of the Sangheili delegates.