In the late 14th century, in the Grand Duchy of Lithuania, Vytautas the Great reformed the Grand Duchy's army: instead of calling all men to arms, he created forces comprising professional warriors—bajorai ("nobles"; see the cognate "boyar"). As there were not enough nobles, Vytautas trained suitable men, relieving them of labor on the land and of other duties; for their military service to the Grand Duke, they were granted land that was worked by hired men (veldams). The newly formed noble families generally took up, as their family names, the Lithuanian pagan given names of their ennobled ancestors; this was the case with the Goštautai, Radvilos, Astikai, Kęsgailos and others. These families were granted their coats of arms under the Union of Horodlo (1413).
WHo reformed the grand duchy army?
Vytautas the Great

Antonio Vivaldi composed a mandolin concerto (Concerto in C major Op.3 6) and two concertos for two mandolins and orchestra. Wolfgang Amadeus Mozart placed it in his 1787 work Don Giovanni and Beethoven created four variations of it. Antonio Maria Bononcini composed La conquista delle Spagne di Scipione Africano il giovane in 1707 and George Frideric Handel composed Alexander Balus in 1748. Others include Giovani Battista Gervasio (Sonata in D major for Mandolin and Basso Continuo), Giuseppe Giuliano (Sonata in D major for Mandolin and Basso Continuo), Emanuele Barbella (Sonata in D major for Mandolin and Basso Continuo), Domenico Scarlatti (Sonata n.54 (K.89) in D minor for Mandolin and Basso Continuo), and Addiego Guerra (Sonata in G major for Mandolin and Basso Continuo).
What two artists created four variations of the Concerto in C Major Op 3 6?
Don Giovanni and Beethoven

According to a study by the China Earthquake Administration (CEA), the earthquake occurred along the Longmenshan fault, a thrust structure along the border of the Indo-Australian Plate and Eurasian Plate. Seismic activities concentrated on its mid-fracture (known as Yingxiu-Beichuan fracture). The rupture lasted close to 120 sec, with the majority of energy released in the first 80 sec. Starting from Wenchuan, the rupture propagated at an average speed of 3.1 kilometers per second 49° toward north east, rupturing a total of about 300 km. Maximum displacement amounted to 9 meters. The focus was deeper than 10 km.
Along what fault line did the quake happen?
Longmenshan fault