Nobility titles and ranks vary depending on the country or ruling country. Of interest is also the history of when a title was invented. Usually a prevailing King or Queen could elevate a person to the peerage, as a reward, traditionally for defending their rulership through military service. However,t some families were so established long ago, the reasons why they are considered royal, or aristocracy, or noble, may be lost. They may have been from a founding tribe or clan, or have won or acquired great wealth and power. When men died out, the line might have been transferred through a woman's line. Hard to argue with someone who can build a fortress of stone when you live in a wood hut.
That changed in recent time to a reward for noteworthy success, consider the various celebrity entertainers such as musicians and actors who became Sir's during Queen Elizabeth's reign... Sir Paul McCartney (James Paul McCartney) for an example. However, very many of those who she elevated were known for service to the Kingdom or humanity, such as Sir Bob Geldof ( Robert Frederick Zenon Geldof.) Their wives are known as Ladies.
There are two types of peers who can be elevated.
Those who were born into it are recognized as HEREDITARY peers.
Those who were not, are called LIFE peers.
