paragraph_text: At the beginning of World War I, East Prussia became a theatre of war when the Russian Empire invaded the country. The Russian Army encountered at first little resistance because the bulk of the German Army had been directed towards the Western Front according to the Schlieffen Plan. Despite early success and the capture of the towns of Rastenburg and Gumbinnen, in the Battle of Tannenberg in 1914 and the Second Battle of the Masurian Lakes in 1915, the Russians were decisively defeated and forced to retreat. The Russians were followed by the German Army advancing into Russian territory.

paragraph_text: Errol Osbourne Nolan II (born August 18, 1991) is an American born sprinter of Jamaican descent who holds dual citizenship with both countries. He now competes for Jamaica as of 2012. He specialises in the 200 and 400 metres.

paragraph_text: On 14 June, while the world's attention was focused on the fall of Paris to Nazi Germany a day earlier, the Soviet military blockade on Estonia went into effect, two Soviet bombers downed the Finnish passenger aeroplane "Kaleva" flying from Tallinn to Helsinki carrying three diplomatic pouches from the US delegations in Tallinn, Riga and Helsinki. On 16 June, the Soviet Union invaded Estonia. The Red Army exited from their military bases in Estonia on 17 June. The following day, some 90,000 additional troops entered the country. In the face of overwhelming Soviet force, the Estonian government capitulated on 17 June 1940 to avoid bloodshed.

paragraph_text: Telman Mardanovich Ismailov (, ; born 26 October 1956) is an Azerbaijani-born businessman and entrepreneur of Mountain Jew origin. Since Azerbaijan does not allow dual citizenship, he holds Russian-Turkish citizenship. He is the chairman of the Russian AST Group of companies, which is active in many countries. Until 2009, Ismailov owned the Europe's then-largest marketplace, Cherkizovsky Market, located in Moscow, Russia.

paragraph_text: Kull began intensive study of public opinion in the Muslim world in 2006, conducting focus groups in six majority-Muslim nations and polls in eleven countries, of which the result is "Feeling Betrayed", his book on Muslim attitudes toward the United States.

paragraph_text: The presence of Islam in Guam is quite small, centered on the island's only mosque, the Masjid Al-Noor in Mangilao. Muslims in Guam are from a wide variety of backgrounds, both originating in traditionally Muslim countries, as well as Chamorro converts and mainland Americans.

paragraph_text: The country with the single largest population of Muslims is Indonesia in Southeast Asia, which on its own hosts 13% of the world's Muslims. Together, the Muslims in the countries of the Malay Archipelago (which includes Brunei, Singapore, Malaysia, Indonesia, the Philippines and East Timor) constitute the world's second or third largest population of Muslims. Here Muslims are majorities in each country other than Singapore, the Philippines, and East Timor.

paragraph_text: In some Muslim countries DST is temporarily abandoned during Ramadan (the month when no food should be eaten between sunrise and sunset), since the DST would delay the evening dinner. Ramadan took place in July and August in 2012. This concerns at least Morocco and Palestine, although Iran keeps DST during Ramadan. Most Muslim countries do not use DST, partially for this reason.

paragraph_text: Albano Carrisi (Italian: [alˈbaːno karˈriːzi]; born 20 May 1943), better known as Al Bano, is an Italian recording artist, actor, and winemaker. In 2016, he was awarded Albanian citizenship due to his close ties with the country.

paragraph_text: The Battle of Las Navas de Tolosa, known in Arab history as the Battle of Al-Uqab (), took place on 16 July 1212 and was an important turning point in the "Reconquista" and in the medieval history of Spain. The Christian forces of King Alfonso VIII of Castile were joined by the armies of his rivals, Sancho VII of Navarre, Peter II of Aragon and Afonso II of Portugal, in battle against the Almohad Muslim rulers of the southern half of the Iberian Peninsula. The Caliph al-Nasir ("Miramamolín" in the Spanish chronicles) led the Almohad army, made up of people from the whole Almohad empire. Most of the men in the Almohad army came from the African side of the empire.

paragraph_text: Al-Mu'tadid was the son of al-Muwaffaq, who was the regent and effective ruler of the Abbasid state during the reign of his brother, Caliph al-Mu'tamid. As a prince, the future al-Mu'tadid served under his father during various military campaigns, most notably in the suppression of the Zanj Rebellion, in which he played a major role. When al-Muwaffaq died in June 891 al-Mu'tadid succeeded him as regent. He quickly sidelined his cousin and heir-apparent al-Mufawwad, and when al-Mu'tamid died in October 892, he succeeded to the throne. Like his father, al-Mu'tadid's power depended on his close relations with the army. These were first forged during the campaigns against the Zanj and were reinforced in later expeditions which the Caliph led in person: al-Mu'tadid would prove to be the most militarily active of all Abbasid caliphs. Through his energy and ability, he succeeded in restoring to the Abbasid state some of the power and provinces it had lost during the turmoil of the previous decades.

paragraph_text: Under al-Mu'tadid he served as commander of the caliph's personal guard and led various expeditions against Bedouins and other restive elements in Iraq, while al-Muqtafi dispatched him in 906 against the Qarmatians. After al-Muqtafi's death, he played a decisive role in the suppression of the palace coup that briefly deposed al-Muqtadir in favour of Abdallah ibn al-Mu'tazz. He was then named treasurer ("khazin") and chief of security ("sahib al-shurta") to the Caliph. He died in 914.

paragraph_text: Battle of Namaraq () (634 CE) was a conflict between Muslims and the Sasanians that occurred in Namaraq, near modern-day Kufa (Iraq). During the Khilafat of Abu Bakr, Muslims under the command of Musana and Khalid bin Walid conquered Al-Hirah, a part of the Persian Empire. The Persians became furious and determined to recover Al-Hirah from the Muslims. Rostam Farrokhzād, a famous Sasanian general, sent some of his relatives from the Ispahbudhan family along with some Persian generals. Khalid bin Walid had already left for Syria so Musana had to fight alone. Umar sent Abu Ubaid with reinforcements. In the battle that followed the Persians were defeated.

paragraph_text: Mayer () is a town in northern Syria, administratively part of the A'zaz District of Aleppo Governorate, located northwest of Aleppo. Nearby localities include Kafr Naya to the northeast and Nubl to the west. According to the Syria Central Bureau of Statistics, Mayer had a population of 4,772 in the 2004 census.

paragraph_text: The Battle of Walaja () was a battle fought in Mesopotamia (Iraq) in May 633 between the Rashidun Caliphate army under Khalid ibn al-Walid and Al-Muthanna ibn Haritha against the Sassanid Empire and its Arab allies. In this battle the Sassanid army is said to have been at least three times the size of the Muslim army.

paragraph_text: Advances were made in irrigation and farming, using new technology such as the windmill. Crops such as almonds and citrus fruit were brought to Europe through al-Andalus, and sugar cultivation was gradually adopted by the Europeans. Arab merchants dominated trade in the Indian Ocean until the arrival of the Portuguese in the 16th century. Hormuz was an important center for this trade. There was also a dense network of trade routes in the Mediterranean, along which Muslim countries traded with each other and with European powers such as Venice, Genoa and Catalonia. The Silk Road crossing Central Asia passed through Muslim states between China and Europe.

paragraph_text: The Book of Roads and Kingdoms (, "Kitāb al-Masālik w’al- Mamālik") is a 9th-century geography text by the Persian geographer Ibn Khordadbeh. It maps and describes the major trade routes of the time within the Muslim world, and discusses distant trading regions such as Japan, Korea, and China. It was written during the reign of Al-Mu'tamid in around 870 CE, while its author was Director of Posts and Police for the Abbasid province of Djibal.

paragraph_text: Since he took power in 1995, Hamad bin Khalifa al-Thani believed Qatar could find security only by transforming itself from a Saudi appendage to a rival of Saudi Arabia. Saudi Arabia withdrew its ambassador to Doha from 2002 to 2008 to try to pressure Qatar to curb its individualistic tendencies. This approach broadly failed. The Arab Spring left a power vacuum which both Saudi Arabia and Qatar sought to fill, with Qatar being supportive of the revolutionary wave and Saudi Arabia opposing it; since both states are allies of the United States, they avoid direct conflict with one another. Qatar has had differences with other Arab governments on a number of issues: it broadcasts Al Jazeera; it is accused of maintaining good relations with Iran; and it has supported the Muslim Brotherhood in the past. Qatar has been accused of sponsoring terrorism. Some countries have faulted Qatar for funding rebel groups in Syria, including al-Qaeda’s affiliate in Syria, the al-Nusra Front, although the Saudis have done the same. Qatar has allowed the Afghan Taliban to set up a political office inside the country. Qatar is a close ally of the United States, hosting the largest American base in the Middle East, Al Udeid Air Base.

paragraph_text: The Muslim conquest of the Levant (Arabic: اَلْـفَـتْـحُ الْإٍسْـلَامِيُّ لِـلـشَّـامِ ‎, Al - Faṫṫḥul - Islāmiyyuash - Shām) or Arab conquest of the Levant (Arabic: اَلْـفَـتْـحُ الْـعَـرَبِيُّ لِـلـشَّـامِ ‎, Al - Faṫṫḥul - ʿArabiyyu Lish - Shām) occurred in the first half of the 7th century, and refers to the conquest of the region known as the Levant or Shaam (Arabic: شَـام ‎, 'Syria'), later to become the Islamic Province of Bilad al - Sham, as part of the Islamic conquests. Arab Muslim forces had appeared on the southern borders even before the death of prophet Muhammad in 632, resulting in the Battle of Mu'tah in 629, but the real invasion began in 634 under his successors, the Rashidun Caliphs Abu Bakr and Umar ibn Khattab, with Khalid ibn al - Walid as their most important military leader.

paragraph_text: In October 2012 the number of ongoing conflicts in Myanmar included the Kachin conflict, between the Pro-Christian Kachin Independence Army and the government; a civil war between the Rohingya Muslims, and the government and non-government groups in Rakhine State; and a conflict between the Shan, Lahu and Karen minority groups, and the government in the eastern half of the country. In addition al-Qaeda signalled an intention to become involved in Myanmar. In a video released 3 September 2014 mainly addressed to India, the militant group's leader Ayman al-Zawahiri said al-Qaeda had not forgotten the Muslims of Myanmar and that the group was doing "what they can to rescue you". In response, the military raised its level of alertness while the Burmese Muslim Association issued a statement saying Muslims would not tolerate any threat to their motherland.

Question: When did Muslim armies invade the country containing Mayer and the country of the man who followed the reign of Al-Mu'tamid?
Answer: in 634