During the 18th century, a new activity flourished in the territory – slave trade. In fact, as the exploitations in Brazil required more workers, the Portuguese started capturing natives in the interior and selling them as slaves. Moreover, despite the agreements that were signed, in mid 19th century, between Portugal and England to put an end to this kind of trade, the truth is that the clandestine slave trade remained until the first decades of the 20th century. Back in the 19th century, Portugal had to face another setback in Mozambique: in the south-east region, a few tribes started a series of conflicts, with attacks perpetrated by the emerging kingdom of the Zulus and by the peoples Zwangendaba and Soshangane (which refused the Portuguese colonial rule). The Soshanganes were responsible for the foundation of the state of Gaza, in southern Mozambique. This state was only to be dismantled in 1897 by the Portuguese, which regained full control of the country.
The Mozambican borders were defined by diplomatic agreements between Portugal and the United Kingdom (in which Portugal was forced to give in to the British demands, because of the great amount of money that Portugal owed to Britain), and the development of the country was due to the implementation of large private companies that invested in agriculture, mining and roads and railways. These companies grew thanks to forced labour, high taxes and low salaries. The situation didn’t change with the Portuguese coup of 1926, which established a dictatorship (later called Estado Novo - New State) that started controlling directly the colonies, including Mozambique. The Portuguese government put an end to the grants to private companies and introduced protectionist policies at the time of the Great Depression, in 1930. These measures resulted in an accumulation of capital that was only to be invested in the 1950s, in large projects for the development of transport infra-structures. This investment happened in a time when thousands of Portuguese started arriving at the territory, looking to take advantage of the opportunities that the New State was offering. These opportunities did not apply to the Mozambicans, and this aspect of the Portuguese overseas policy brought about the first separatist ideals. These ideals were consolidated, in 1962, with the foundation of the Front for the Liberation of Mozambique (FRELIMO), which, after some internal disagreements, eventually initiated a strategy of armed guerrilla in 1964. This war, for Portugal, was one more conflict to add to the list of confrontations in the other Portuguese colonies in Africa.
The coup that took place in Portugal on April 25th 1974 overthrew the New State’s dictatorship and established democracy, making way for a decolonisation process. FRELIMO, taking advantage of their military positions in the north and centre Mozambique, led the independence process and declared, on June 25th 1975, the Popular Republic of Mozambique as an independent state with a Constitution that prohibited other parties apart from FRELIMO itself. However, not long after the independence, Mozambique had to face a civil war between FRELIMO and the Mozambican National Resistance (RENAMO). The latter was supported by the governments of Rhodesia and South Africa (in response to FRELIMO, which supported both the Rhodesian oppositionist guerrilla and ANC), and also by former Portuguese settlers and some strata of the Mozambican population. This conflict had devastating consequences for the country, and not even the Nkomati agreement, signed in 1984, which determined the end of the South African support to RENAMO, was enough to end the war in Mozambique. The situation was only to be resolved with the peace treaty signed between FRELIMO and RENAMO, on October 4th 1992, following a change in the constitution that authorized other political forces besides FRELIMO. On October 27th and 28th 1994 Mozambicans voted for the first time in free elections for the Government and for the Presidency. FRELIMO (44,3%) and its leader Joaquim Chissano (53,3%) won the elections. On the other side, RENAMO and its leader Afonso Dhlakama (which had, respectively, 33,7% and 37,7% of the votes), acknowledged and accepted FRELIMO’s victory, expressing their commitment to demobilize their military forces. The government expressed the exact same commitment.
This political and social stability encouraged foreign investment in the territory. Britain was among the major investors, by forgiving a part of Mozambique’s debt and by donating an enormous amount of capital. These initiatives strengthened the relationship between the two countries and, in 1995, Mozambique entered the Commonwealth, without changing, however, its official language, that is still Portuguese.