Is it true that HIV/AIDS was first found in primate species?!

Is it true that HIV/AIDS was first found in primate species?

To be precise, HIV (HUMAN immunodeficiency) has not been found in primate species, but ancestor-viruses to HIV have been found. It is sort of like a family tree but of viruses....the fuield of molecular genetics has transformed and illuminated the history of many viruses.

It is widely believed that HIV-1 and HIV-2 entered the human population from at least two different African primate species. Some studies suggest that this happened in the early-mid 20th century while other studies point to a time in the past 100-200 years (from the research, I support the 100-200 year window.

SIV (SIMIAN immuno...) is a virus that has been found to be the "parent" of HIV (albeit distant). At some point it mutated inside of the primate and became infectious to humans. This transmission was most likely the result of hunters being exposed to the blood of primates when hunting/cleaning the food (primate). It probably happened a few times over the past few hundred years and began living in the human population unnoticed (most people had fewer sex partners, science/technology wasn't able to determine cause of death at the time.

It wasn't until two major shifts occured simultaneoulsy on two separate continents that HIV became an epidemic. The sexual revolution in the 60s and 70s created an environment that HIV took advantage of. Multiple sexual partners, unsafe sex, the "no worries, we have antibiotics" mindframe.
In Africa, the civil wars (rape), poverty, migrant worker populations among others contributed to an environment where HIV could and did spread.

That is my take on it from all the research I have read (I've read a lot!!!) But there are still unanswered questions