The British government departments spent approximately $204 million (£161.7 million) on the state funeral of Queen Elizabeth, according to the British Treasury. The Home Office, responsible for police and national security, accounted for the largest share of £73.7 million from the total amount. The Treasury's Chief Secretary, John Glen, stated in a written statement to Parliament, "The government's priorities were to ensure that these matters proceeded smoothly and with an appropriate level of dignity, while ensuring the safety and security of the public at all times." At that time, the London police announced that the funeral was the largest security event in their history, attended by prominent figures from around the world. Following the death of the longest-reigning British monarch at the age of 96 on September 8, the country entered a national mourning period of ten days, culminating in her formal burial on September 19. During this period, Queen Elizabeth's coffin remained at St. Giles' Cathedral in Edinburgh before being transported to London, where around 250,000 people waited for hours to pay their respects at Westminster Hall before her burial.