BANGKOK — With the gilded pageantry of a bygone era, the cremation ceremony of King Bhumibol Adulyadej of Thailand began in earnest on Thursday. Hundreds of thousands of black-clad mourners lined the streets of Bangkok to honor him and catch a glimpse of the royal chariot transporting his funerary urn to a 164-foot-high pyre.

The colorful spectacle — with its golden spires, vermilion-costumed soldiers, marigold garlands, saffron-robed monks and royal guards in crimson hats — contrasted with the somber mood of a nation that has mourned ever since King Bhumibol’s death on Oct. 13, 2016, at 88 years old.

King Bhumibol, also known as Rama IX, was the world’s longest-reigning monarch, having spent seven decades on the throne. On Thursday, the yearlong national mourning period officially ended. Most Thais had known no other king when he died, and for many uncertainty about the kingdom’s future endures.