How was Gran Colombia formed in 1819?

The formation of Gran Colombia in 1819 was a pivotal development in the revolutionary struggle against Spanish rule in South America. Following a period of civil war and Spanish reconquest in New Granada, republican forces led by Francisco de Paula Santander reorganized in the llanos of Casanare and joined the forces of Simón Bolívar in the Orinoco basin of Venezuela.12

In 1819, these revolutionary leaders completed arrangements for a regular government and convened a constitutional convention at Angostura (now Ciudad Bolívar, Venezuela), which included delegates from Casanare and various Venezuelan provinces. This Congress of Angostura laid the foundation for the Republic of Colombia, later known as Gran Colombia, which encompassed the territories of modern-day Colombia, Panama, Venezuela, and Ecuador.312

Bolívar further solidified this effort in 1819 by invading Colombia and securing a decisive victory against Spanish forces at the Battle of Boyacá on August 7. While the republic was initially governed by a highly centralized military structure, it was definitively organized by the Congress of Cúcuta in 1821.123