Books about colonialism, slavery and Irish history

I’m looking for books about colonialism, like western colonialism starting from the 15/1600’s, especially Europe’s part as a whole. Not only Britain.
How the world looked during these times. And I want to go deep into it, like not only the surface but also things that are generally unknown.

I’m also looking for books about slavery outside of the Atlantic slave trade. Maybe this sounds weird but I want to know the horrors of it that are not widely known, the stuff that happened that’s generally suppressed.

Also books about specifically Irish history and the colonization of Ireland.

I know there’s a lot of books out there and I get overwhelmed not knowing what books are the best ones.
I would like the books to be unbiased too.

Thank you in advance!