The increase in world tin prices also helped to stabilize Bolivia's economy, which had been near collapse during the first revolutionary presidency of Víctor Paz Estenssoro.

When Paz Estenssoro jailed several militant labour activists, miners in Catavi mines responded by seizing a group of hostages, including four US citizens.

The Bolivian army, which had been rebuilt and increased in size during recent years, provided an alternative power base to Paz Estenssoro.

After some hesitation, air force General René Barrientos was picked by Paz Estenssoro as his running mate for the May 1964 elections, and the army became more involved in the politics.

After armed clashes between the army and miners on October 28, Barrientos and Ovando decided to strike and launched their coup on November 3.

By the evening all the major military units had backed the coup and on in the afternoon of November 4 Paz Estenssoro with his family was exiled to Lima, as Barrientos and Ovando established their junta.

It was Ovando who publicly announced formation of the junta but by the evening of the 4th the more popular and constitutionally acceptable vice-president Barrientos emerged as the leader.

[4] Elections were held in July 1966, and Barrientos, as the presidential candidate of the Front of the Bolivian Revolution, won with 67% of vote and was officially inaugurated on August 6, 1966.