Portuguese Augustinian involvement in Africa and the Gulf followed on the heels of Portuguese territorial footholds in the region.
Naval explorer and seafarer Vasco de Gama, sailing from Lisbon on 8th July 1497, sailed around the Cape of Good Hope and anchored at Mozambique in March 1498.
He proceeded thence to Kilwa and Mombasa, then flourishing cities, and to Malindi.
From there he sailed to Calicut in India (28th May 1498).
In 1499 de Gama returned and took possession of Zanzibar, where he established an Augustinian convent.
These religious settled at Paté and Mombasa, while the Dominicans settled at Mozambique and the Jesuits in the valley of the Zambesi.
This was not a vision of Christian mission with the more nobile nature of later centuries.
The Portuguese mentality of the day was predatory more than developmental, and some of its citizens were ready to use the "advancement of Christian religion" as a cover for getting rich quickly by plundering the Muslim ports.
The Portuguese attitude towards the Muslim religion was hostile because of the negative collective memory of the Muslim occupation of Portugal not many generations beforehand.
Timeline of Portuguese Activity in East Africa, 1498-1700. By Jim Jones of West Chester University.
Map of Africa. On a map of this small magnification, centres where Portuguese Augustinians ministered in the 17th-18th centuries are not marked. Moving anti-clockwise from left to right (i.e., west to east), these places are: Sao Tome, an island in the South Atlantic Ocean off the coast of Gabon, in the Congo and Angola on the mainland just south of today's Gabon, Zanzibar, an island in the Indian Ocean off the coast of Tanzania, Mombasa, an island slightly further north, off the coast of Kenya, Muscat (Oman) in the Gulf of Oman at the top of the Arabian Sea.