Toscanini Online says:
Arturo Toscanini was born in the city of Parma, in Italy’s fertile Po plain, on March 25,1867.
Toscanini quickly established himself as the first Italian conductor of world-class talent who was as interested in foreign repertoire as in domestic works, in symphonic music as in opera, in the classics as in the moderns. He performed Wagner’s music with passion and intellectual rigor – in Toscanini’s student days Wagner had embodied Europe’s musical avant-garde – but he performed with equal passion and rigor the works of many composers whom Wagner had detested, notably Verdi and Brahms. In the lyric theatre, which had often been held hostage by star singers and their caprices, Toscanini gradually imposed a system in which solo voices, chorus, orchestra, stage movement, sets, costumes, and lighting were all given maximum attention in order to create what Wagner had called the Gesamtkunstwerk – the complete work of art. At the same time he began to demand more highly skilled playing from orchestra musicians than his predecessors had considered necessary. To his way of thinking, the sense and spirit of a piece of music could not be expressed if the notes were not played in tune, with their proper rhythmic values, at a tempo close to the one indicated by the composer, and in correct textural balance against all the other notes being played at the same time. All of this was merely a point of departure for achieving something much deeper and more valuable, but it was nevertheless a sine qua non. To achieve all of these goals Toscanini fought great battles, and his terrifying temper became a legend in the musical world. The result, however, is that most professional musicians from his day to ours – even those who disagree with his recorded interpretations – are direct beneficiaries of his lifelong struggle.
See also the bio on ClassicalNotes.net.