World's Longest Reigning Monarch Is Dead.

The world's longest reigning monarch is dead. The king of Thailand, Bhumibol Adulyadej, died at age 88 on Thursday, according to the bureau of the royal household. The king had been in poor health for a long time, primarily spending his last years in a Bangkok hospital.

King Bhumibol Adlyadej

Worries about the king's condition heightened after a Sunday night health bulletin was issued by the palace, stating that his medical team had performed kidney dialysis and replaced a tube used to drain fluid from his lung when his blood pressure dropped, and placed the monarch on a ventilator. Even after the procedures, his condition was "not stable," the palace said.

Hundreds of Thais dressed in pink prayed for the king's recovery Wednesday and Thursday outside Siriraj hospital in Bangkok

King Bhumibol ascended to the throne 70 years ago, making him the world's longest-reigning living monarch, before his death.

The king died at 3:52 p.m. local time and passed away in a "peaceful manner," the Royal Palace said, as thousands waited outside the hospital where he lay in nervous anticipation of the news.

The 70th anniversary of his accession was celebrated in Thailand on June 9 with millions of his subjects donning yellow shirts for the day.