Filipino Sultan Bantilan Esmail Kiram II, third from left, gestures beside members of the Muslim Royal clan during a press conference at the financial district of Makati, south of Manila, Philippines.

The leader of a sultanate in the southern Philippines that staged a 2013 invasion of a bustling Malaysian state and sparked a deadly security crisis has died of kidney failure, his family and followers said Sunday.

Sultan Esmail Kiram II died at age 76 late Saturday at a hospital in southern Zamboanga city and left an order for his sultanate and followers to pursue a claim to Sabah state in neighboring Malaysia, according to sultanate spokesman Abraham Idjirani.

“One of his instructions was the pursuit of the Sabah claim through peaceful means for the welfare of the Filipino people,” Idjirani said.

Although largely dismissed as a vestige from a bygone era, Kiram’s Muslim sultanate, based in the southern Philippine province of Sulu, stirred up a crisis between Malaysia and the Philippines when his younger brother and about 200 followers, dozens of them armed, barged into Sabah’s coastal village of Lahad Datu in February 2013.

Malaysia responded by sending troops and launching airstrikes in weeks of sporadic fighting that killed dozens of people before the standoff eased.

Kiram’s younger brother who led that invasion survived the intense clashes and managed to return home in the southern Philippines, where he died last year of a heart attack, Idjirani said.

Malaysia has governed the resource-rich frontier Sabah region of timberlands and palm oil plantations in northern Borneo as its second-largest federal state since the 1960s.

The Kiram sultanate, which emerged in the 1400s, built a legend for its wide influence at the time and its feared Tausug warriors. Chinese and European leaders once sent vassals to pay homage to their powerful forebears. The Sulu sultanate preceded both the Philippine republic and Malaysia by centuries, Idjirani said.

Overrun by history, however, the Kirams now carry royal titles and nothing much else. The sultanate has about 75,000 followers in Sulu and outlying islands that are among the country’s poorest regions and are troubled by Muslim rebels, al-Qaida-linked extremists and outlaws.

Kiram led the Sulu-based sultanate since the early 2000s, helped by an elder brother, Jamalul, who had lived for years in Manila’s metropolis, where he died in 2013.

Kiram’s successor will be a younger brother, Phugdal Kiram, a former grade school teacher and basketball player, Idjirani said.

The Kirams claim Sabah has belonged to their sultanate for centuries and was only leased to Malaysia, which they say pays them a paltry annual rent. Malaysian officials contend the payments are part of an arrangement under which the sultanate has ceded the 74,000 square kilometers (28,000 square miles) of Sabah territory to their country.

Philippine presidents have relegated the volatile territorial feud to the backburner despite efforts by the Kirams to put it on the national agenda.