Complex sentence: In July 1995, Williams was photographed by the press partying with Oasis at Glastonbury Festival which was the month the band offering him an ultimatum; where he was to adhere to the band's responsibilities or to leave before their scheduled world tour.
Split into simpler sentences: In July 1995, Williams was photographed by the press partying with Oasis at Glastonbury Festival. This led to the band offering him an ultimatum; where he was to adhere to the band's responsibilities or to leave before their scheduled world tour.