There are also certain concepts that different people never thought of as immoral, but up until our time (out time not included) are considered immoral.
Your use of the word “considered” makes me beleve they we are using two different definitions of the word “morality”. When I use the term morality I am refering to “descriptive morality” which Wikipedia explains as:
In its “descriptive” sense, morality refers to personal or cultural values, codes of conduct or social mores that distinguish between right and wrong in the human society. Describing morality in this way is not making a claim about what is objectively right or wrong, but only referring to what is considered right or wrong by people. For the most part right and wrong acts are classified as such because they are thought to cause benefit or harm, but it is possible that many moral beliefs are based on prejudice, ignorance or even hatred. This sense of the term is addressed by descriptive ethics.
You seem to define moratity as “normative morality” which is described as following:
In its “normative” sense, morality refers directly to what is right and wrong, regardless of what specific individuals think. It could be defined as the conduct of the ideal “moral” person in a certain situation. This usage of the term is characterized by “definitive” statements such as “That act is immoral” rather than descriptive ones such as “Many believe that act is immoral.” It is often challenged by moral nihilism, which rejects the existence of an any moral truths, and supported by moral realism, which supports the existence of moral truths. The normative usage of the term “morality” is addressed by normative ethics.