Complex sentence: After the New Zealand Government declared war on Germany and made the decision to establish a New Zealand Expeditionary Force for overseas service, the Wellington Mounted Rifle Regiment was formed and began concentrating at Awapuni racecourse in Palmerston North from 12 August 1914.
Split into simpler sentences: After the New Zealand Government declared war on Germany it decided to establish the New Zealand Expeditionary Force for overseas service. As a part of this force, the Wellington Mounted Rifle Regiment was formed and began concentrating at Awapuni racecourse in Palmerston North from 12 August 1914.