Complex sentence: Scalloway is the largest settlement on Shetland's Atlantic coast with about 1000 people and until 1708 was the capital of Shetland (now Lerwick, on the East coast of the Shetland Mainland).
Split into simpler sentences: Scalloway is the largest settlement on Shetland's Atlantic coast with a population of approximately 1,000 people. Until 1708 was the capital of the Shetland Islands (now Lerwick, on the east coast of the Shetland Mainland).