Key Facts
- Operation start date
- 13 September 1961
- Pedra Verde reoccupied
- 20 September 1961
- Artillery deployed
- Six 7.5 cm and two 8.8 cm howitzers
- Guerrilla casualties (estimated)
- Hundreds, per UPA POW accounts
- Strategic route controlled
- Coffee Road (Luanda to Carmona/Uíge)
Strategic Narrative Overview
Initial Portuguese reconnaissance by the 96th Caçadores Battalion was repelled by enemy fire. A follow-up probe by the experienced 4th Caçadores Especiais Company on 26 July resulted in hours of combat before the Portuguese withdrew due to ammunition shortages. A subsequent major assault on 10 September by the Caçadores Especiais Battalion No. 261 was also fought back with considerable Portuguese losses. Operation Esmeralda formally launched on 13 September 1961, with artillery support from Field Artillery Group No. 157.
01 / The Origins
Following their expulsion from Nambuangongo during Operation Viriato, UPA guerrillas established a fortified base at the Pedra Verde mountain range in Angola. The remote, forested terrain gave the guerrillas a natural stronghold where they built a training camp and a weapons workshop producing handmade firearms. The area's position on the Coffee Road, linking Luanda to Carmona and surrounding plantations, made it of high strategic and economic importance to Portugal.
03 / The Outcome
Portuguese forces advanced under artillery cover and reached Pedra Verde on 16 September without resistance, fully reoccupying it on 20 September 1961. Surviving UPA guerrillas fled and joined an estimated 150,000 Bakongo refugees in Congo-Kinshasa. The UPA subsequently shifted to launching smaller cross-border raids from bases near the frontier, leaving the Portuguese in control of Pedra Verde and the Coffee Road corridor.
Belligerents & Mobilization Analysis
Side A
1 belligerent
Henrique de Oliveira Rodrigues, Armando Maçanita, Luís Artur Carvalho Teixeira de Morais, João de Madureira Fialho Prego.
Side B
1 belligerent
Kinetic Engagement Axis
Scroll horizontally to view full axis. Events plotted relatively.