Short answers, pulled from the story.
Archaeological evidence from Kilu Cave on Buka Island reveals human presence in the Solomon Islands between 30,000 and 28,000 BC. Sea levels were lower during this Pleistocene era, physically joining Buka and Bougainville to the southern Solomons as one landmass known as Greater Bougainville.
Spanish navigator Álvaro de Mendaña de Neira was the first European to visit the islands, sailing from Peru in 1568. He landed on Santa Isabel on the 7th of February and explored several other islands including Makira, Guadalcanal, and Malaita.
From 1942 until the end of 1943, the Solomon Islands became the scene of several major land, sea, and air battles between Allies and the Empire of Japan. The Japanese launched Operation Mo in May 1942, occupying Tulagi and most of the western Solomon Islands including Guadalcanal where they began work on an airstrip.
The country was granted independence on the 7th of July 1978 under terms of the Solomon Islands Act 1978. The first prime minister was Sir Peter Kenilorea of the Solomon Islands United Party while Elizabeth II became Queen represented locally by a Governor General.
Initial civil unrest was characterized by fighting between the Isatabu Freedom Movement also known as the Guadalcanal Revolutionary Army and the Malaita Eagle Force. For many years people from Malaita had been migrating to Honiara and Guadalcanal attracted primarily by greater economic opportunities causing tensions with native Guadalcanal islanders known as Guales.