If you mean 26th great grandparents, those are in the mid-1200's to early 1300's.
You can only get back that far if your ancestors have ties in England.
For many you can get all the original records, birthdates down to the day, what cemetery they are buried in, etc.
After the mid-1200's, surnames were rare, so if one was added, it was often the city in which the child was born. So if the parents moved around a lot, each child could have a different surname. Sometimes also they changed surnames as they gained titles.
The Earl of Windsor may also be the Duke of Lancaster, and the Prince of Westmoreland.
Then to complicate the matter even further. He could be Edward the 5th Earl of Windsor, Edward the 23rd Duke of Lancaster, and Edward the 34th Prince of Westmoreland, not to be confused with King Edward the 3rd, or Edward the 7th Earl of Windsor, hi hi...
Nevertheless, the English maintained excellent records and cross-references through many different sources, and ironically most of them agree with each other too.
Doing genealogy is almost like working a crossword puzzle going by the clues.
You may pick up someones wife's first name from one document, her surname from another document, and her nickname or common use name from yet another document. Cemetery records often only give the wife's married name.
Now if you really want to add a twist. Many changed or shortened their names when they moved from one area to another, and almost always when they move across an ocean. Aleavinea may become Alicea and later Alice. Willem almost always become William, and often the spelling of surnames is altered when a new language is encountered to make them easier to pronounce.
Gottliebsdotter, my take her fathers name of Johannson, which may become Johnson, or simply John.
In my own family, one of my ancestors named Gottliebe Andreas Schaumberger totally changed his name first to Franz Berg when he boarded the ship to America, then to Francis Berg when he moved further west, then to Frank Berg when he finally settled in Missouri. I know this because of our family records.
I run across genealogy files by others that show this person as three or four different individuals, and use kids that belong to someone else by the same name as their kids. This is the reason I ignore most of what people have put together when doing research. Sometimes their records may give me a possible name to search when I'm at a dead end, but I never go by what they say unless I can find verification that also cross-verifies to other records considered accurate or close to accurate.
One thing really sad I discovered when I placed my files on Ancestry dot com, is folks simply copy and paste anything and everything they can find creating hundreds of fake trees, I assume just because they are bored and want to mess people up.
You have no idea how many I've run across that have tons of children born to parents 50 to 100 years before their parents were born, hi hi... Or children born to parents that have been dead for 50 to 100 years or more.
If they find a name, let's say John Smith as an example. Any time they find someone named John Smith, they say YES that is our John Smith and add ALL the data for each John Smith as the data for their John Smith, no matter how far off base it is.
Poor John Smith! He is Black, White, Aztec, Croatian, been married 46 times, and has 215 children, and he only lived to be 30 years old, during a time span which spreads from 1326 to 1985, hi hi... And oh, his fathers, all 87 of them, were all over 400 years old when John Smith was born...
I'm not perfect either, and have found more mistakes in my files than I care to admit, but many of them came due to merges of family members that looked right, and once merged, they are almost impossible to undo.
Ironically, I found a few of my merges I thought were wrong turned out to be correct. He really did have four different wives. Or vice versa, she really did have four different husbands and reused her favorite children's names with each husband.
Genealogy makes people go bald, hi hi...