Complex sentence: In 1879, in the sacristy, the famous "Codex Rossanensis" was discovered: it is a Greek parchment manuscript of Matthew and Mark, written in silver on purple-stained parchment, one of the oldest pictorial Gospels known.
Split into simpler sentences: In 1879, the famous "Codex Rossanensis" was discovered in the sacristy. It is a Greek parchment manuscript of Matthew and Mark, written in silver on purple-stained parchment, and is one of the oldest pictorial Gospels known.