This question can be answered in two ways, "yes" and "no."
First it is based on the beliefs of the people involved. Some people do not accept people who were not actually born into the family. For those people, the spouse of an aunt or uncle is not your uncle or aunt.
On the other hand, some people accept the spouse, and believe that after marriage, they are related to them. Common usage in the English language follows this pattern. Your father's sister, for example is your aunt. If she marries, you speak of her and her husband as "aunt and uncle."
Your aunts and uncles are the sisters and brothers of your parents. So they are "blood related." But you also call the husband of your mother's sister your uncle, and he is not "blood related." So aunts and uncles are not always really related to you.
A modified extended family is made up when children get married and also get their own children. This makes the initial parents to become grandparents and the siblings become uncles and aunts.
great great (etc.) grandparents great grandparents grandparents + great uncles and great aunts parents + uncles and aunts [=parents' siblings] siblings + cousins [=uncles' and aunts' children] children + nephews and nieces [=siblings' children] grandchildren great gandchildren great great (etc.) grandhildren also cousins and second cousins [=(great-)grandparents' descendants]
great great (etc.) grandparents great grandparents grandparents + great uncles and great aunts parents + uncles and aunts [=parents' siblings] siblings + cousins [=uncles' and aunts' children] children + nephews and nieces [=siblings' children] grandchildren great gandchildren great great (etc.) grandhildren also cousins and second cousins [=(great-)grandparents' descendants]
Your father's uncle's uncle is the son of your great great grandfather. He may be your great grandfather or he may be another brother of your great grandfather, and thus your great great uncle.Your father's uncle also has aunts and uncles from the other side of his family. That is, he has uncles who are brothers of that one of his parents who is not a descendant of your great great grandfather. Those uncles are not related to you at all.
People are treated equally by there job, and many people have a family so thats equal to others. Some people aren't treated equally, but treat others the way you would like to be treated. Also many people are aunts, uncles, mothers, fathers, oldest child, youngest, middle. Some people are grandparents. And that is equal to others. Hopefully that was helpful :)
That was the case at one time. Nowadays, all monarchies require the successors to be legitimate. (Remember that aunts, uncles and cousins can also be in the line of succession.)
Anyone descended from a brother or sister of one of your direct ancestors is your cousin. There are different names for different kinds of cousins. For example, your first cousins are the children of your aunts and uncles. Your second cousins are the grandchildren of your great aunts and great uncles. Your parents'first cousins are your first cousins, once removed. And the children of your first cousins are also your first cousins, once removed.
General Billy Mitchell's uncle was U.S. Senator John L. Mitchell from Wisconsin. He was also distantly related to Frederick W. Mitchell, the mayor of Milwaukee, Wisconsin.
Your aunt is the sister of either your father or your mother. If your aunt is your father's sister, then your father's cousin is also her cousin. If your aunt is your mother's sister, then she is not related to your father's cousin.
B. Two parents, biological children, and grandparents from both sides
Relatives are people who are related, that is, within the same family or connected by marriage or adoption. They include parents, grandparents, aunts, uncles, and various levels of cousins. They can also include half-brothers and half-sisters (who share one common parent), and stepparents or stepchildren, who usually have only a legal relationship rather than a biological one.