Born in Königsaue and educated as a surgeon, Busch emigrated from Imperial Germany to eastern Bolivia [es] during the Amazon rubber boom.

During the Acre War, Busch lent logistical support to the Bolivian expeditionary force commanded by President José Manuel Pando.

Paul Busch was born on 4 November 1867 in Königsaue, an agrarian settlement in the fertile Magdeburg Börde, near the eponymous city, in what is now the Bördeland Municipality of Saxony-Anhalt.

[2] His father, Ferdinand Busch, was Kapellmeister of St. John's [de], the Lutheran church in neighboring Eickendorf, and taught music and mathematics there and in the adjacent villages.

[13] From there, he traveled by land through the northern Argentine trail, passing the cities of Rosario, Santa Fe, and Santiago del Estero toward the Bolivian frontier.

In a tale recounted by historian Mario Gabriel Hollweg, Busch purportedly fractured one bandit's skull with his cane and delivered the other to the police himself.

[9] Upon his arrival in Bolivia, Busch settled in Santa Cruz de la Sierra, a then-remote city isolated from the Andean west [es] but which benefitted from the flourishing rubber boom.

[14] There, Busch developed a close friendship with Wálter Villinger, a compatriot emigrant from Biberach an der Riß in Baden, who invited him to enter business with one Emilio Zeller.

[18] Over the following years, Busch navigated the many tributaries of the Amazon basin, which connected isolated communities to the major eastern population centers.

[19] According to Hollweg, his penchant for accurate diagnoses, efficient treatments, and therapeutic accomplishments led superstitious minds to label him a "witch or curandero".

His recurrent medical expeditions and business ventures on behalf of Zeller led him to frequent several riverside communities in the departments of Beni and Santa Cruz, especially Baures, the site of his trade office, and San Javier, where he owned a residence.

The dispute centered around armed attempts by separatist Brazilian filibusters to seize control of Bolivia's rubber-rich northern territories [es].

[21] Bolivian forces drew sizable volunteer support from German expats, many of whom were employed by foreign and national corporations operating in the region.

His successful efforts in breaking through the separatist blockade, wherein he was nearly taken prisoner, earned him a personal letter of recognition from President José Manuel Pando, who commanded Bolivian troops in the field.

[23] In 1904, Busch relocated to Baures in the Iténez Province, where he worked as branch manager of Zeller & Co., whose local office had become the town's largest trading house.

The attack left Busch gravely wounded in the stomach, but he managed to make port in Puerto Ballivián [es] before being transferred to Trinidad.

He was transported by river from Trinidad to the transatlantic port of Belém do Pará and spent thirty days in agony aboard a German steamship bound for Hamburg.

He spent the next few years in convalescence in Germany, where medical expenses forced him to sell off his stocks in Zeller & Co.[27] Busch reentered Beni by way of the Madeira and Mamoré rivers in either 1910 or 1911.

[29] He spent short stints in the hamlets of Yaguarú and El Puente in Guarayos Province and practiced medicine among the indigenous peoples of the surrounding Franciscan missions.

[46] By the end of his term, the inhabitants of Concepción were on the verge of rebellion and his reputation for ruthlessness reached as far as Santa Cruz de la Sierra.

[66] Busch later narrated that he had given himself one hour for Germán to arrive or else he would commit suicide: "I would shoot myself, because, fallen in the forest and devoured by vermin, [my son] would have died because of me, because of the longing to see his father".

[74] Because of his outsized influence, "it is very probable" that the president's German-born father played a role in the Bolivian government's deepened ties with the Third Reich during this time.

[75] Busch met with multiple German officials on behalf of the administration; he discussed economic relations with Ernst Wendler and Joachim von Ribbentrop and attended an opera with Adolf Hitler, whom he gifted a vicuña wool quilt.

[81] In 1912, Busch married Enriqueta Antelo Hurtado, a woman from Santa Rosa de la Mina, whom he had met a few days prior.

[82] Gustavo studied business management and became a prominent broadcaster and radio personality; he owned the stations Libertad in La Paz and Centenario in Santa Cruz.

[87] Once in Germany, Busch was caught unawares by the outbreak of World War II on 1 September; he remained trapped in the Third Reich for the duration of the conflict.

[89] Upon the war's conclusion, Busch was interned in a British prisoner-of-war camp and was stripped of his diplomatic passport by José Saavedra, an erstwhile political rival of his late son.

[91] Sometime after the war, thanks to the diplomatic efforts of Aniceto Solares, the Bolivian foreign minister who lobbied British authorities, Busch and other nationals were released and repatriated.

[95] For Brockmann, Busch was an "intrepid pioneer ... to whom Bolivia also owes the exploration of many rivers ... at a time when such an adventure required valor and temerity".

[96] His deeds "left legend in San Javier and Concepción, where with a tall hat, surgical case, and rifle, he waged war against the fearsome brigands of those regions", recounts Augusto Céspedes.