You don't even want to know how badly they screwed over Peru.

https://docslib.org/doc/2248959/the-war-of-the-pacific-the-empire-crushes-perus-american-system

It might sound crazy, but they took Peru's shit (literal shit = guano)

To enforce its dictates, the Empire repeatedly tried to bludgeon Peru into submission. In 1849, when Peru tried to restructure an 1822 loan on which it had de-faulted in 1825, British Prime Minister Lord Palmer-ston responded with the warning, accompanied by the deployment of warships to the port of Callao, that the defense of the interests of British bondholders Mc-Clean, Rowe & Co. was considered to be a “matter of state” for Her Majesty’s government. Faced with the “Palmerston Memorandum’s” threat of invasion, the government was forced to agree to a ten-year contract with the London House of Anthony Gibbs & Sons, making it Peru’s chief financial agent in Europe, as well as the sole agent for marketing Peru’s valuable guano deposits in Europe.

They screwed them over in ways you can't even image.

But the imperial usurers were unrelenting. Peru was forced again in 1868 to hand over its financial sovereignty to the French House of Dreyfuss, which was linked to Britain’s Rothschild banking interests. Later, the treacherous W.R. Grace & Co. acted on behalf of British bondholders to sabotage Peru’s ef-forts to obtain weapons during the war, and then im-posed the infamous “Grace Contract” on the nation to secure its submission to the financial vultures in the postwar period.

Peru attempted to get out from the strangehold of the British (Rothschild) banks:

For a period spanning 30 years (1845-76), Presi-dents Castilla, Echenique, Balta, and Pardo fought to free Peru from the death grip of British finance, and build an independent sovereign nation in alliance with a unique group of foreigners dedicated to the republi-can worldview

So the Brits used Chile to crush Peru.

By the eve of the war in 1879, despite imperial pres-sures, Peru had become a continental leader in science, culture, engineering, and medicine, and had progressed toward creating a national banking system. The port of Callao was the site of the most advanced machine-tool center on the subcontinent, allowing it to produce the artillery Peru would later use in the war against the Brit-ish artillery supplied to Chile.

And they leveled Lima.

The ostensible reason for Chile’s April 5, 1879 declaration of war against Peru and Bo-livia was a set of alleged treaty and demarca-tion violations committed by both nations. In reality, the casus belli was the entire Ameri-can System project. When Manuel Pardo na-tionalized the nitrate industry in 1875, fol-lowed by a debt moratorium in 1876, British bondholders demanded blood. They got it two years later, in 1878, when Pardo was as-sassinated, just as he was planning another bid for the Presidency.

The killed him, but they weren't done punished Peru for trying to resist them.

The US tried to help Peru be independent, but the British Empire wanted them obliterated.

The fact that London rejected U.S. efforts to medi-ate an end to the war, on terms that would have been both beneficial and even generous to Chile, while spar-ing Peru any loss of territory, underscored that the Em-pire’s only goal was Peru’s annihilation.

And they succeeded.

“The . . . English bondholders . . . put up the job of this war on Peru. . . . England sweeps it all in. . . . The ironclads that destroyed the Peruvian Navy were fur-nished by England. . . . It is a perfect mistake to speak of this as a Chilean war on Peru. It is an English war on Peru, with Chile as the instrument. . .

Peru had to hand over its railroads to the control of the UK banks.

They took everything and left Peru with nothing for daring to defy the Rothschilds.