There is no precise figures to account for the number of people forcefully taken from their Africa roots to the other parts of the world by the European slave traders. This inhumane enterprise trended between the 16th and 19th centuries.
With rough approximations pitching an excess of 10 million Africans that were abducted from their abodes for the then lucrative trade, It is rather noteworthy to know that not all of the captured Africans lived to get to the purported New World, with some dying to the effect of maltreatments and ailments while aboard on the sea, and some of the slaves threw themselves into the water.
Having this brutal impugn meted out to the Black continent, it is not far fetched that the Europeans are responsible for one of the dreadful savagery pegged in human history. However, the illicit idea that European slave traders were enabled by some African leaders then has been a cloying excuse for an unleashed enterprising assault to avoid morality breach.
A comprehensive perspective on the Transatlantic slave trade (TAST) takes into cognizance what the English, French and others benefited from the trading of African people.
It is actually interesting that although we also know that Portuguese were amongst the slave traders, we seem to know very little about their participation in the TAST. Perhaps for many, this is due to the fact of getting swayed in America’s racial history to the detriment of similar mischief in other places.
But the Portuguese were definitely the worst offenders in the TAST. Below are some facts of their dismal involvement:

The Portuguese led the way
It is best to argue that the brain behind Transatlantic slave trade were the Portuguese. With the blessing of the Catholic Church and the imperial ambitions of Prince Henry the Navigator, the Portuguese are known to have moved the African slaves to Portugal as far back as 1444.
Other participating European nations like the United Kingdom and France got the ugly idea from the Portuguese. But how were the Portuguese the first?
Well, the Portuguese opened the eye of the then lucrative business on their adventure of exploring the world beyond Europe when they became the best seafaring Europeans at the beginning of the 15th century. Exploring new territories came subsequently with desire to colonize peoples and their resources.

It was so profitable that they sold to the Spanish
The Portuguese were so good at securing and transporting enslaved Africans that they were major suppliers to the Spanish. This was definitely a unique arrangement because other Europeans who traded in African slaves traveled to the source.
While there were legitimate slave traders recognized by the Portuguese crown who sold enslaved Africans to Spain, there were those who also sold “contraband slaves” to their Iberian neighbors.
Spain acquired over 500,000 enslaved Africans over 300 years, a large percentage of whom were sold by Portugal.

The Portuguese were successful at imposing new identities
Every enslaved African in any far-away land colonized by Europeans was the holder of a new identity, according to the whims of the slave masters. But because no other country secured slaves from different parts of the continent than the Portuguese, their task of imposing new identities was different.
Interestingly, the Portuguese overcame this task in spite of the fact that Portuguese had among their stock enslaved peoples from Mauritania in Northwest Africa to Mozambique in Southern Africa.

The Portuguese carried the most enslaved Africans
The Portuguese conveyed more enslaved Africans out of the continent than any other European nation. Some historians put the Portuguese consignment of slaves between the 15th and 18th century at more than five million.
The reason of enslaving that en masse is one of of the reasons that the Portuguese colonized Brazil, the biggest expanse of land in South America, in the 16th century, and this meant more hands were needed to support their works.