Who They Are
There have been warring thoughts on what true Anglo-Indians are. English authors are more apt to saying that those of English heritage who were merely born in India, but had no part of the Indian lineage, are Anglo-Indians. Then there are the English rulers who occupied India in order to make it a "more civilized country" who felt that they should be termed as Anglo-Indians for having immersed themselves in the culture. Note that they too did not have any Indian heritage either. But the third group of Anglo-Indians are the ones who have fought to maintain a voice in India, who have been oppressed at various times because of their "mixed breed". These are the very people who by definition are Anglo-Indian; they have an Indian parent and a European parent. For some it meant having British roots, for others Irish, Scottish, German, or Portuguese. Because of being in the minority, they stuck close together to form their own communities, tending to marry within their mixed heritages or marry other races entirely.
Outside of India
Anglo-Indians were not limited to having their roots in India. In fact, many Indian sailors, came to Britain during the 17th century and created a slightly different type of community more heavily focused on English customs. This was seen more during World War I, with much of the British male population away, resulting in a huge boom of Anglo-Indian births and marriages. Then in the 1970's, the Anglo-Indian community flourished further once Indian women began coming to the country.
From the 1940's through the remainder of the 20th century, most of the Anglo-Indians from India migrated to other nations; some intermarried with the local races, while others continued to marry within the Anglo-Indian community. At one time, Anglo-Indians were favored over Indians to run businesses and schools, because of their advantage of their mother-tongue being English and their mannerisms westernized. Unfortunately, after India gained independence in 1947, much of that support for the minority dwindled, and has continued to do so, leaving Anglo-Indians at a disadvantage in regard to employment and education. Students are now required to learn Indian dialects that are foreign to them, since their mother-tongue is English. Employers are more apt to frown down on the Anglo-Indians because of their anglican customs and non-Hindu beliefs. For all these reasons and more, only a small number of Anglo-Indians still live in India. The largest communities are found in Australia, England, Canada, and certain regions of the United States.