Descendants of Mindanao’s Moro Muslims, Christian settlers and Lumad reminded to keep the promise to remain brothers.

North Cotabato, Philippines – Visitors at the brand new Cotabato Museum begin their tour by watching a short animated film.

It’s crude compared with the average Hollywood cartoon flick, but the audience leaves the mini-theatre enchanted.

It tells the legend of two devoted brothers at the time when Islam came to Mindanao, the largest southern island in the Philippines.

One of them, Tabunaway, chose to embrace the new faith while the other, Mamalu, held on to his traditional beliefs.

Their parting of ways eventually set off what would become the bitter conflict that’s tearing their descendants apart to this day.

More than 100,000 people have died in Mindanao’s successive wars since the 1970s, according to several non-government research groups.

A diorama of the North Cotabato province. Moro Muslims and Christian settlers occupy most of the lowlands, including the marshes, while the Lumad live in the mountains. [JC Gotinga/Al Jazeera]

The conflict has also set the region’s economy back by about $14bn.

Although the violence in Mindanao is often characterised as being between its native “Moro” Muslims and Christian settlers from the country’s northern islands, the reality is far more nuanced and complicated.

There is a third voice – the Lumad – caught in the fray.

The Lumad are an indigenous group composed of more than 100 distinct tribes.

In mythology, they are the descendants of Mamalu, who moved to the highlands when Islam became the predominant religion in the lowlands.

The Lumad are gentle by nature, leading simple lives close to nature.

A long history of discrimination and neglect by the government has left them desperately poor and vulnerable to many kinds of abuse, including the usurpation of their ancestral lands.

The Lumad were forced to fight.

In July last year, President Rodrigo Duterte said in a public speech that he would “bomb” the Lumad’s schools because they “spread subversive ideas”, accusing the group of supporting the communist rebels, the New People’s Army (NPA).

At the Cotabato Museum’s inaugural ceremony, Duterte’s secretary for the peace process, Jesus Dureza, said: “More than 70 percent of the NPA’s fighters are Lumads.”

Children performing a traditional dance at the inauguration of the Cotabato Museum. [JC Gotinga/Al Jazeera]

The government has recently reopened channels for peace talks with the communist rebels, and Dureza’s lumping the Lumad with them was not necessarily an indictment.

Many Lumad leaders deny supporting the NPA, but not the fact that they have, in recent years, banded together their own small army to fight for their cause.

Although the Cotabato Museum tells history from three vantage points – the Muslim, Christian and Lumad narratives – it highlights that of the Lumad, not only because it is the least heard among them but also because it is the most ancient.

“Everyone was a Lumad,” said museum co-curator Antonio Montalvan, “and that is what we want the Cotabato people to always remember, that they come from one source.”

As visitors go through the museum’s collection of weapons and implements from Mindanao’s centuries of warfare, they should have in mind that all of it are symbols of a broken vow.

That is if they had paid attention to the animated film at the start of their tour.

Before they parted ways, Mamalu and Tabunaway made a pact of peace – that even though their beliefs had become different, they would forever remain brothers.

The museum challenges their descendants to keep that promise.