Complex sentence: The relationship with Covent Garden continued and the first event held under the St George's Day Events company was on April 23rd 2003, although only a small affair it was the beginning of what was to become the London celebrations.
Split into simpler sentences: The relationship with Covent Garden continued and the first event held under the St George's Day Events company was on 23 April 2003. Although only a small affair, it was the beginning of what was to become the London celebrations.