Complex sentence: The first Conference was held in Brussels, 1991, followed by ICH 2, Orlando, Florida, 1993, ICH 3, Yokohama, Japan 1995 and the Fourth International Conference on Harmonisation, July 1997, was once again in Brussels.
Split into simpler sentences: The first Conference was held in Brussels in 1991, followed by ICH 2 in Orlando, Florida in 1993, and ICH 3 in Yokohama, Japan in 1995. The Fourth International Conference on Harmonisation, in July 1997, was once again in Brussels.