Complex sentence: In the second half of the 20th century, there was significant expansion of the villages and in 1948, the villages of Brightwell and Sotwell were brought together as one unit and, in 1949, the Greenmere estate was built.
Split into simpler sentences: In the second half of the 20th century, there was significant expansion of the villages. In 1948, the villages of Brightwell and Sotwell were brought together as one unit and, in 1949, the Greenmere estate was built.