After John II's death in 1454, he began to actively participate in the noble league fighting against Henry IV of Castile. In 1445, he fought in the First Battle of Olmedo against Alvaro de Luna who supported Henry IV. A year later in 1465, he participated in the so-called Farce of Ávila where a group of Castilian nobles symbolically executed an effigy of Henry IV and proclaimed his half brother, Alfonso of Castile, better known as "Alfonso the Innocent", to be the lawful king. The ceremony was called the "Farce of Avila" by contemporary critics and the name has thus passed into history. For his participation in the "Farce", he received the title of Constable of Castile