Question: When was the southern tip of the continent that contains the river that the Tekezé turns into, colonized?

full_context: Document 1: Yangtze: The river originates from several tributaries in the eastern part of the Tibetan Plateau, two of which are commonly referred to as the ``source ''. Traditionally, the Chinese government has recognized the source as the Tuotuo tributary at the base of a glacier lying on the west of Geladandong Mountain in the Tanggula Mountains. This source is found at 33 ° 25 ′ 44'' N 91 ° 10 ′ 57 ''E ﻿ / ﻿ 33.42889 ° N 91.18250 ° E ﻿ / 33.42889; 91.18250 and while not the furthest source of the Yangtze, it is the highest source at 5,342 m (17,526 ft) above sea level. The true source of the Yangtze, hydrologically the longest river distance from the sea, is at Jari Hill at the head of the Dam Qu tributary, approximately 325 km (202 mi) southeast of Geladandong. This source was only discovered in the late 20th century and lies in wetlands at 32 ° 36 ′ 14'' N 94 ° 30 ′ 44 ''E ﻿ / ﻿ 32.60389 ° N 94.51222 ° E ﻿ / 32.60389; 94.51222 and 5,170 m (16,960 ft) above sea level just southeast of Chadan Township in Zadoi County, Yushu Prefecture, Qinghai. As the historical spiritual source of the Yangtze, the Geladandong source is still commonly referred to as the source of the Yangtze since the discovery of the Jari Hill source.
Document 2: Tekezé River: The Tekezé River rises in the central Ethiopian Highlands near Mount Qachen within Lasta, from where it flows west, north, then west again, forming the westernmost border of Ethiopia and Eritrea from the confluence of the Tomsa with the Tekezé at to the tripoint between the two countries and Sudan at . After entering northeastern Sudan at the tripoint it joins the Atbarah River, which is a tributary of the Nile. The Tekezé is perhaps the true upper course of the Atbarah, as the former follows the longer course prior to the confluence of the two rivers.
Document 3: Birbir River: The Birbir River of southwestern Ethiopia is a tributary of the Baro River, which it creates when it joins the Gebba at latitude and longitude . It is politically important because its course defines part of the boundary between the Mirab Welega and Illubabor Zones of the Oromia Region.
Document 4: Flooding of the Nile: The flooding of the Nile is the result of the yearly monsoon between May and August causing enormous precipitations on the Ethiopian Highlands whose summits reach heights of up to 4550 m (14,928 ft). Most of this rainwater is taken by the Blue Nile and by the Atbarah River into the Nile, a less important amount is flowing through the Sobat and the White Nile into the Nile. During this short period, those rivers contribute up to ninety percent of the water of the Nile and most of the sedimentation carried by it, but after the rainy season, dwindle to minor rivers.
Document 5: Medjerda River: The Medjerda River (), the classical Bagrada, is a river in North Africa flowing from northeast Algeria through Tunisia before emptying into the Gulf of Tunis and Lake of Tunis. With a length of , it is the longest river of Tunisia. It is also known as the Wadi Majardah or Mejerha ().
Document 6: British Empire: At the end of the 16th century, England and the Netherlands began to challenge Portugal's monopoly of trade with Asia, forming private joint-stock companies to finance the voyages—the English, later British, East India Company and the Dutch East India Company, chartered in 1600 and 1602 respectively. The primary aim of these companies was to tap into the lucrative spice trade, an effort focused mainly on two regions; the East Indies archipelago, and an important hub in the trade network, India. There, they competed for trade supremacy with Portugal and with each other. Although England ultimately eclipsed the Netherlands as a colonial power, in the short term the Netherlands' more advanced financial system and the three Anglo-Dutch Wars of the 17th century left it with a stronger position in Asia. Hostilities ceased after the Glorious Revolution of 1688 when the Dutch William of Orange ascended the English throne, bringing peace between the Netherlands and England. A deal between the two nations left the spice trade of the East Indies archipelago to the Netherlands and the textiles industry of India to England, but textiles soon overtook spices in terms of profitability, and by 1720, in terms of sales, the British company had overtaken the Dutch.
Document 7: Sobat River: The Sobat River is a river of the Greater Upper Nile region in northeastern South Sudan, Africa. It is the most southerly of the great eastern tributaries of the White Nile, before the confluence with the Blue Nile.
Document 8: Atbarah River: The Atbarah River (; transliterated: Nahr 'Atbarah) in northeast Africa rises in northwest Ethiopia, approximately 50 km north of Lake Tana and 30 km west of Gondar. It flows about 805 km (500 mi) to the Nile in north-central Sudan, joining it at the city of Atbarah (). The river's tributary, the Tekezé (Setit) River, is perhaps the true upper course of the Atbarah, as the Tekezé follows the longer course prior to the confluence of the two rivers (at 14° 10' N, 36° E) in northeastern Sudan. The Atbarah is the last tributary of the Nile before it reaches the Mediterranean.
Document 9: History of South Africa: The establishment of the staging post by the Dutch East India Company at the Cape in 1652 soon brought the Khoikhoi into conflict with Dutch settlers over land ownership. Cattle rustling and livestock theft ensued, with the Khoikhoi being ultimately expelled from the peninsula by force, after a succession of wars. The first Khoikhoi - Dutch War broke out in 1659, the second in 1673, and the third 1674 -- 1677. By the time of their defeat and expulsion from the Cape Peninsula and surrounding districts, the Khoikhoi population was decimated by a smallpox epidemic, against which the Khoikhoi had no natural resistance or indigenous medicines. The disease had been brought to the Cape by Dutch sailors.
Document 10: Walaqa River: The Walaqa River, a tributary of the Blue Nile, is river in the Amhara Region of Ethiopia. Wegde is located to its north. Mida Woremo and Dera are to the south, while Kelala is to the northeast. The Walaqa River may have been the northern boundary of the historical province of Walaqa.
Document 11: History of the Cape Colony before 1806: The written history of the Cape Colony in what is now South Africa began when Portuguese navigator Bartolomeu Dias became the first modern European to round the Cape of Good Hope in 1488. In 1497, Vasco da Gama sailed along the whole coast of South Africa on his way to India, landed at St Helena Bay for 8 days, and made a detailed description of the area. The Portuguese, attracted by the riches of Asia, made no permanent settlement at the Cape Colony. However, the Dutch East India Company (VOC) settled the area as a location where vessels could restock water and provisions.
Document 12: Great Trek: Voortrekkers Voortrekkers great exodus of 1837 - 1838 from the British Cape Colony to find Boer autonomy and freedom Date 1837 - 1838 Location Cape Colony, Southern Africa, British Empire Participants Boer farmers Outcome Boers achieved autonomy and freedom from British colonial rule by establishing an independent Boer republic in the hinterland of South Africa Deaths Boers, Zulus, Bantus, Hottentots
Document 13: Nile: The Nile (Arabic: النيل‎, written as al-Nīl; pronounced as an-Nīl) is a major north-flowing river in northeastern Africa, and is the longest river in Africa and the disputed longest river in the world (Brazilian government claims that the Amazon River is longer than the Nile). The Nile, which is about 6,650 km (4,130 mi) long, is an "international" river as its drainage basin covers eleven countries, namely, Tanzania, Uganda, Rwanda, Burundi, the Democratic Republic of the Congo, Kenya, Ethiopia, Eritrea, South Sudan, Republic of the Sudan and Egypt. In particular, the Nile is the primary water source of Egypt and Sudan.The river Nile has two major tributaries, the White Nile and Blue Nile. The White Nile is considered to be the headwaters and primary stream of the Nile itself. The Blue Nile, however, is the source of most of the water and silt. The White Nile is longer and rises in the Great Lakes region of central Africa, with the most distant source still undetermined but located in either Rwanda or Burundi. It flows north through Tanzania, Lake Victoria, Uganda and South Sudan.  The Blue Nile begins at Lake Tana in Ethiopia and flows into Sudan from the southeast. The two rivers meet just north of the Sudanese capital of Khartoum.The northern section of the river flows north almost entirely through the Sudanese desert to Egypt, then ends in a large delta and flows into the Mediterranean Sea. Egyptian civilization and Sudanese kingdoms have depended on the river since ancient times. Most of the population and cities of Egypt lie along those parts of the Nile valley north of Aswan, and nearly all the cultural and historical sites of Ancient Egypt are found along river banks.
Document 14: British Empire: The Dutch East India Company had founded the Cape Colony on the southern tip of Africa in 1652 as a way station for its ships travelling to and from its colonies in the East Indies. Britain formally acquired the colony, and its large Afrikaner (or Boer) population in 1806, having occupied it in 1795 to prevent its falling into French hands, following the invasion of the Netherlands by France. British immigration began to rise after 1820, and pushed thousands of Boers, resentful of British rule, northwards to found their own—mostly short-lived—independent republics, during the Great Trek of the late 1830s and early 1840s. In the process the Voortrekkers clashed repeatedly with the British, who had their own agenda with regard to colonial expansion in South Africa and with several African polities, including those of the Sotho and the Zulu nations. Eventually the Boers established two republics which had a longer lifespan: the South African Republic or Transvaal Republic (1852–77; 1881–1902) and the Orange Free State (1854–1902). In 1902 Britain occupied both republics, concluding a treaty with the two Boer Republics following the Second Boer War (1899–1902).
Document 15: Sahara: The desert comprises much of North Africa, excluding the fertile region on the Mediterranean Sea coast, the Atlas Mountains of the Maghreb, and the Nile Valley in Egypt and Sudan. It stretches from the Red Sea in the east and the Mediterranean in the north to the Atlantic Ocean in the west, where the landscape gradually changes from desert to coastal plains. To the south, it is bounded by the Sahel, a belt of semi-arid tropical savanna around the Niger River valley and the Sudan Region of Sub-Saharan Africa.
ground_truth: 1652
sub_queries: What river does Tekezé River turn into? Answer: Atbarah River
Atbarah River >> continent Answer: Africa
When was the southern tip of Africa colonized? Answer: 1652