Problem: Background: Sir Edward William Elgar, 1st Baronet  (2 June 1857 - 23 February 1934) was an English composer, many of whose works have entered the British and international classical concert repertoire. Among his best-known compositions are orchestral works including the Enigma Variations, the Pomp and Circumstance Marches, concertos for violin and cello, and two symphonies. He also composed choral works, including The Dream of Gerontius, chamber music and songs. He was appointed Master of the King's Musick in 1924.
Context: During the 1890s, Elgar gradually built up a reputation as a composer, chiefly of works for the great choral festivals of the English Midlands. The Black Knight (1892) and King Olaf (1896), both inspired by Longfellow, The Light of Life (1896) and Caractacus (1898) were all modestly successful, and he obtained a long-standing publisher in Novello and Co. Other works of this decade included the Serenade for Strings (1892) and Three Bavarian Dances (1897). Elgar was of enough consequence locally to recommend the young composer Samuel Coleridge-Taylor to the Three Choirs Festival for a concert piece, which helped establish the younger man's career. Elgar was catching the attention of prominent critics, but their reviews were polite rather than enthusiastic. Although he was in demand as a festival composer, he was only just getting by financially and felt unappreciated. In 1898, he said he was "very sick at heart over music" and hoped to find a way to succeed with a larger work. His friend August Jaeger tried to lift his spirits: "A day's attack of the blues ... will not drive away your desire, your necessity, which is to exercise those creative faculties which a kind providence has given you. Your time of universal recognition will come."  In 1899, that prediction suddenly came true. At the age of forty-two, Elgar produced the Enigma Variations, which were premiered in London under the baton of the eminent German conductor Hans Richter. In Elgar's own words, "I have sketched a set of Variations on an original theme. The Variations have amused me because I've labelled them with the nicknames of my particular friends ... that is to say I've written the variations each one to represent the mood of the 'party' (the person) ... and have written what I think they would have written - if they were asses enough to compose". He dedicated the work "To my friends pictured within". Probably the best known variation is "Nimrod", depicting Jaeger. Purely musical considerations led Elgar to omit variations depicting Arthur Sullivan and Hubert Parry, whose styles he tried but failed to incorporate in the variations. The large-scale work was received with general acclaim for its originality, charm and craftsmanship, and it established Elgar as the pre-eminent British composer of his generation.  The work is formally titled Variations on an Original Theme; the word "Enigma" appears over the first six bars of music, which led to the familiar version of the title. The enigma is that, although there are fourteen variations on the "original theme", there is another overarching theme, never identified by Elgar, which he said "runs through and over the whole set" but is never heard. Later commentators have observed that although Elgar is today regarded as a characteristically English composer, his orchestral music and this work in particular share much with the Central European tradition typified at the time by the work of Richard Strauss. The Enigma Variations were well received in Germany and Italy, and remain to the present day a worldwide concert staple.
Question: What did people think about his work?
Answer: recommend the young composer Samuel Coleridge

Problem: Background: The Aztecs (), were a Mesoamerican culture that flourished in central Mexico in the post-classic period from 1300 to 1521, during the time in which a triple alliance of the Mexica, Texcoca and Tepaneca tribes established the Aztec empire. The Aztec people were certain ethnic groups of central Mexico, particularly those groups who spoke the Nahuatl language and who dominated large parts of Mesoamerica from the 14th to the 16th centuries. Aztec culture is the culture of the people referred to as Aztecs, but since most ethnic groups of central Mexico in the postclassic period shared basic cultural traits, many of the traits that characterize Aztec culture cannot be said to be exclusive to the Aztecs. For the same reason, the notion of "Aztec civilization" is best understood as a particular horizon of a general Mesoamerican civilization.
Context: In the first 50 years after the founding of the Mexica dynasty, the Mexica were a tributary of Azcapotzalco, which had become a major regional power under the ruler Tezozomoc. The Mexica supplied the Tepaneca with warriors for their successful conquest campaigns in the region and received part of the tribute from the conquered city states. In this way, the prestige and economy of Tenochtitlan gradually grew.  In 1396, at Acamapichtli's death, his son Huitzilihhuitl (Nahuatl: "Hummingbird feather") became ruler; married to Tezozomoc's daughter, the relation with Azcapotzalco remained close. Chimalpopoca (Nahuatl: "She smokes like a shield"), son of Huitzilihhuitl, became ruler of Tenochtitlan in 1417. In 1418, Azcapotzalco initiated a war against the Acolhua of Texcoco and killed their ruler Ixtlilxochitl. Even though Ixtlilxochitl was married to Chimalpopoca's daughter, the Mexica ruler continued to support Tezozomoc. Tezozomoc died in 1426, and his sons began a struggle for rulership of Azcapotzalco. During this struggle for power, Chimalpopoca died, probably killed by Tezozomoc's son Maxtla who saw him as a competitor.  Itzcoatl, brother of Huitzilihhuitl and uncle of Chimalpopoca, was elected the next Mexica tlatoani. The Mexica were now in open war with Azcapotzalco and Itzcoatl petitioned for an alliance with Nezahualcoyotl, son of the slain Texcocan ruler Ixtlilxochitl against Maxtla. Itzcoatl also allied with Maxtla's brother Totoquihuaztli ruler of the Tepanec city of Tlacopan. The Triple Alliance of Tenochtitlan, Texcoco and Tlacopan besieged Azcapotzalco, and in 1428 they destroyed the city and sacrificed Maxtla. Through this victory Tenochtitlan became the dominant city state in the Valley of Mexico, and the alliance between the three cities provided the basis on which the Aztec Empire was built.  Itzcoatl proceeded by securing a power basis for Tenochtitlan, by conquering the city-states on the southern lake - including Colhuacan, Xochimilco, Cuitlahuac and Mizquic. These states had an economy based on highly productive chinampa agriculture, cultivating floating gardens in the shallow lake Xochimilco. Itzcoatl then undertook further conquests in the valley of Morelos, subjecting the city state of Cuauhnahuac (today Cuernavaca).
Question: What lakes did the peple conqured are called
Answer:
Colhuacan, Xochimilco, Cuitlahuac and Mizquic.