Complex sentence: Ever since, Corsican nationalism has been a feature of the island's politics, with calls for greater autonomy and protection for Corsican culture and the Corsican language, and flares of raids and killings, culminated with the assassination of Prefect Claude Érignac in 1998.
Split into simpler sentences: Ever since, Corsican nationalism has been a feature of the island's politics, with calls for greater autonomy and protection for Corsican culture and the Corsican language. Periodic flare-ups of raids and killings culminated in the assassination of Prefect Claude Érignac in 1998.