Islam spread to the region during the 13th century AD and Philippine sultanates were established, like that of Sulu and Maguindanao. In the late 16th to early 17th century, first contact with Spain occurred, with Spanish forces trying to occupy the area.
Today the region is home to most of the country's Muslim or Moro populations, composed of many ethnic groups such as the Maranao and the Tausug, the Banguingui (users of the vinta), as well as the collective group of indigenous tribes known as the Lumad.
Contrary to common belief, only a portion of Mindanao was inhabited by Muslims by the time the Spanish arrived and colonized the Philippines, and centuries after the first native was converted to Islam. In fact, most of the people in the northern and eastern part of the island practiced native religions before they converted to Christianity. Japanese and government forces failed to quell the desire for separation from the largely Christian nation by Muslim factions on the island. Due to an influx of migration, as well as evangelization, the majority of Mindanao's population is now predominantly Christian. Filipino Muslims have portrayed the history of the island to imply that Christianity displaced Islam, which is true in many cases. Although, the religions are not the central issue of the thirty year old conflict, the issue is land and ethnically based rather than religiously based.
The island group of Mindanao encompasses Mindanao island itself and the Sulu Archipelago to the southwest. The island group is divided into six regions, which are further subdivided into 25 provinces.
The mountains of Mindanao can be conveniently be grouped into five ranges, including both complex structural mountains and volcanoes. The structural mountains on the extreme eastern and western portions of the island show broad exposures of Mesozoic rock with ultrabasic rocks at the surface in many places along the east coast. Surface rock in other areas of the island is mainly Tertiary and Quarternary volcanic or sedimentary.
Paralleling the east coast, from Bilas Point in Surigao del Norte to Cape Agustin in southeast Davao, is a range of complex mountains known in their northern portion as the Diwata Mountains. This range is low and rolling in its central portion. A proposed road connecting Bislig on the east coast with the Agusan River would pass through a ten-mile broad saddle across the mountains at a maximum elevation of less than 250 meters while the existing east-west road from Lianga, 30 air miles north of Bislig, reaches a maximum elevation of only 450 meters. The Diwata Mountains, north of these low points, are considerably higher and more rugged, reaching an elevation of 2,012 meters in Mount Hilonghilong, 17 miles northeast of Butuan City. The southern portion of this east coast range is broader and even more rugged than the northern section. In eastern Davao, several peaks rise above 2,500 meters and one unnamed mountain rises to 2,810 meters.
The east facing coastal regions of Davao and Surigao del Sur are marked by a series of small coastal lowlands separated from the other by rugged forelands which extend to the water’s edge. Offshore are numerous coral reefs and tiny islets. This remote and forbidding coast is made doubly difficult to access during the months from October to March by the heavy surf driven before the northeast trades. A few miles offshore is found the Mindanao or Philippine Deep. This ocean trench, reaching measured depths of 35,400 feet, marks one of the greatest depths known on the earth’s surface.
A second north-south range extends along the western borders of Agusan and Davao provinces from Camiguin Island in the north to Tinaca Point in the south. This range is mainly structural in origin, but it also contains at least three active volcano peaks. In the central and northern portions of this range, there are several peaks between 2,000 and 2,500 meters and here the belt of mountains is about 30 miles across. West of the city of Davao two active volcanoes, Mount Talomo at 2,693 meters and Mount Apo at 2,954 meters, the highest point in the Philippines, dominate the skyline, South of Mount Apo, this central mountain belt is somewhat lower than it is to the north, with peaks averaging 1,100 and 1,800 meters only.
In Western Mindanao, a range of complex structural mountains forms the long, hand-like Zamboanga Peninsula. These mountains, reaching heights of only 1,200 meters, are not as high as the other structural belts in Mindanao. In addition, there are several places in the Zamboanga Mountains where small inter-mountain basins have been created, with some potential for future agricultural development. The northeastern end of this range is marked by the twin peaks of the now extinct volcano, Mount Malindang, which rise splendidly behind Ozamis City to a height of 2,425 meters. Mount Dapia is the highest mountain in the Zamboanga Peninsula reaching a height of 2,617 meters (8,586 ft). Meanwhile, Batorampon Point is the highest mountain of the southernmost end of the peninsula reaching a height of only 1,335 meters (4,380 ft) located in the boundery of Zamboanga City.
A series of volcanic mountains is found near Lake Lanao in a broad arc through Lanao del Sur, northern Cotabato and western Bukidnon provinces. At least six of the twenty odd peaks in this area are active and several are very impressive as they stand in semi-isolation. The Butig Peaks, with their four crater lakes, are easily seen from Cotabato. Mount Ragang, an active volcano cone, reaching 2,815 meters is the most isolated, while the greatest height is reached by Mount Kitanglad at 2,896 meters.
In southwestern Cotabato, still another range of volcanic mountains is found, this time paralleling the coast. These mountains have a maximum extent of 110 miles from northwest to southeast and measure some 30 miles across. The best known mountain here is Mount Parker whose almost circular crater lake measures a mile and a quarter in diameter and lies 300 meters below its 2,040 meter summit.
A second important physiographic division of Mindanao is the series of upland plateaus in Bukidnon and Lanao del Sur provinces. These plateaus are rather extensive and almost surround several volcanoes in this area. The plateaus are comprised of basaltic lava flows interbedded with ash and volcanic tuff. Near their edges the plateaus are cut by deep canyons and at several points spectacular waterfalls drop to the narrow coastal plain. These falls hold considerable promise for development of hydroelectric energy. Indeed, one such site at Maria Cristina Falls has already become a major producer. Because the rolling plateaus lie at an elevation averaging 700 meters above sea level, they offer relief from the often oppressive heat at the coastal lowlands. Lake Lanao occupies the major portion of one such plateau in Lanao del Sur. This largest lake on Mindanao and second in the country is roughly triangular in shape with an 18-mile long base. Having a surface at 780 meters above sea level, and being rimmed on the east, south and west by series of peaks reaching 2,300 meters, the lake provides a scenic grandeur and pleasant temperature seldom equaled in the country. Marawi City, at the northern tip of the lake, is bisected by the Agus River which feeds the Maria Cristina Falls.
Another of Mindanao’s spectacular waterfall sites is located in Malabang, 15 miles south of Lake Lanao. Here the Jose Abad Santos Falls present one of the nation’s scenic wonders at the gateway to a 200-hectare national park development.
Mindanao contains two large inland lowland areas, the valleys of the Agusan and Mindanao rivers in Agusan and Cotabato Provinces, respectively. There is some indication that the Agusan Valley occupies a broad syncline between the central mountains and the east coast mountains. This valley measures 110 miles from south to north and varies from 20-30 miles in width. Thirty five miles north of the head of Davao Gulf lay the watershed between the Agusan and the tributaries of the Libuganon River which flows to the Gulf. The elevation of this divide is well under 200 meters indicating the almost continuous nature of the lowland from the Mindanao Sea on the north to the Davao Gulf.
The Mindanao River and its main tributaries, the Catisan and the Pulangi, form a valley with a maximum length of 120 miles and a width which varies from 12 miles at the river mouth to about 60 miles in central Cotabato. The southern extensions of this Cotabato Valley extends uninterrupted across a 350 meter watershed from Illana Bay on the northwest to Sarangani Bay on the southeast.
Other lowlands of a coastal nature are to be found in various parts of Mindanao. Many of these are tiny isolated pockets, as along the northwest coast of Zamboanga. In other areas such as the Davao Plain, these coastal lowlands are as much as ten miles wide and several times that length.
From Dipolog eastward along the northern coast of Mindanao almost to Butuan City extends a rolling coastal plain of varying width. In Misamis Occidental, the now dormant Mt. Malindang has created a lowland averaging eight miles in width. Shallow Panquil Bay divides this province from Lanao del Norte, and is bordered by low lying, poorly drained lowlands and extensive mangroves. In Misamis Oriental, the plain is narrower and in places almost pinched out by rugged forelands which reach to the sea. East of Cagayan de Oro City, a rugged peninsula extends well into the Mindanao Sea.
The island group of Mindanao is an arbitrary grouping of islands in the Southern Philippines which encompasses six administrative regions. These regions are further subdivided into 25 provinces, of which only four are not on Mindanao island itself. Some of the areas are semi-autonomous Muslim areas. The island group includes the Sulu Archipelago to the southwest, which consists of the major islands of Basilan, Jolo, and Tawi-Tawi, plus outlying islands in other areas such as Camiguin, Dinagat, Siargao, Samal. The Limunsudan Falls, with an approximate height of 800 ft, is the highest water falls in the Philippines located at Iligan City.
The six regions are:
The major conurbation on Mindanao is Davao City, the country's largest city by area, with a population of approximately 1.3 million.
The Cebuano language is spoken by the majority in Mindanao. Cebuano is generally the native language in most regions, except for Muslim areas on the west coast, and among the hill tribes.
Christians form the majority with 63% of the population, Muslims 32% (mostly on the southern part of the island), other 5%.
The native Maguindanaon and other native Muslim/non-Muslim groups of Mindanao have a culture that is different from the main cultures of the Southern Philippines.