Complex sentence: In the year 1851, the watch-making industry was introduced to the small city of Grenchen, Switzerland, where many famous watch companies were founded, helping to make Grenchen an important part of today's Swiss watch business.
Split into simpler sentences: In the year 1851, the watch-making industry was introduced to the small city of Grenchen Switzerland. Many famous watch companies were founded here and have helped make Grenchen an important part of today's Swiss watch business.