Complex sentence: The campaign opened on 1 May 1945 when the 26th Brigade Group landed on the small island of Tarakan off the east coast of Borneo to secure the island's airstrip as a base to support the planned landings at Brunei and Balikpapan.
Split into simpler sentences: The campaign opened on 1 May 1945 when the 26th Brigade Group landed on the small island of Tarakan off the east coast of Borneo. The goal of this operation was to secure the island's airstrip as a base to support the planned landings at Brunei and Balikpapan.