Complex sentence: She was built by HMNB Portsmouth; her keel was laid in January 1912, she was launched ten months later, and was commissioned into the Home Fleet in March 1914 as the fleet flagship.
Split into simpler sentences: She was built by HMNB Portsmouth, and her keel laid in January 1912. Launched ten months later, she was commissioned into the Home Fleet in March 1914 as the fleet flagship.