He was a trusted advisor in the Norman Kingdom of Sicily at the time of its fall to Henry VI, Holy Roman Emperor (1194).
When Henry was marching to besiege Naples in 1191, Salerno sent a letter promising him its loyalty and the Archbishop Nicholas, hostile to Germans, abandoned the faithless city for Naples, where he took control of the city's defences after Richard, Count of Acerra, was wounded.
Together, he and the ammiratus ammiratorum Margaritus of Brindisi successfully defended the ancient city and forced Henry to lift the siege.
The empress was released the next year; Henry was crowned on 25 December 1194 in Palermo, with not only Nicholas, but Richard, Margaritus, and Queen Sibylla present.
Four days later, they were all arrested on charges of conspiracy (probably trumped up) and shipped off to German prisons.