Complex sentence: He then convened a Synod at Udayamperoor, south of Ernakulam, from 20--26 June 1599, known as the Synod of Diamper.
Split into simpler sentences: He then convened a Synod at Udayamperoor, south of Ernakulam, from 20--26 June 1599. This is known as the Synod of Diamper.