Complex sentence: At one of the most spectacular Japanese sword exhibitions recently at the British Museum, London, England, one of the masterpieces was displayed was a Kanenobu, made around 1688-1704-the third generation Kanenobu.
Split into simpler sentences: At one of the most spectacular Japanese sword exhibitions was recently held at the British Museum in London, England. One of the masterpieces was displayed was a Kanenobu sword, made around 1688-1704, which is a the third generation Kanenobu.