How far back is realistic?

[Biggles50]

Back to the pleistocene? That’s when it gets easier!

Given that we all have 2 parents, 4 grandparents, 8 great grandparents etc., you’ll see that our ancestors at least double with every generation - e.g. you have 1,048,576 GGGGGGGGGGGGGGGGGGgrandparents and that’s only 20 generations! Taking it back to the end of the pleistocene, would give you at least 480 generations and more direct ancestors that you could shake a stick at.

My point - go back far enough and you’re descended from everyone.

Yes

A genealogist once worked out that over 95% of white Europeans have a direct line to King Edward III.

[Vance Mead]

It depends on what sort of people they were. For most people - yeoman, carpenter, butcher, etc - you probably won't get back before about 1550. Parish records began in 1538, but for only a relatively small number of parishes. There are muster rolls and tax lists (lay subsidies) in the 1520s and 1540s. Some of these are available online, for example for Buckinghamshire. Some yeomen and husbandmen back to the early 1500s left wills.

For landowners - gentry, knights, squires- there are inquisitions post mortem, legal records, wills, and heralds' visitations, which might get you back to the early 1400s.

If you connect to aristocrats and royals, you could get back to Charlemagne and his ancestors, about the year 600. But there are a lot of bogus genealogies connecting to royalty.

[Erato]

Take the appropriate mtDNA test and it will give you the route all the way back to Mitochondrial Eve.

We don't even need a DNA test to say that all of us can trace our lineage back, back, back into the Precambrian ooze.

[Vance Mead]

The original question included the word "realistic".

[Zefiro]

I am wondering how far back is realistic?

There's no such thing as realistic expectations. You start searching and you'll see what comes your way. Enjoy the trip instead of focusing on the destination.

I think it'd be cool to be able to trace one's geneology all the way back to Christ but maybe that's just a pipe dream?

It's way cooler to expand laterally. Pay tribute to all the siblings of your direct ancestors by researching them and including them in your tree. Don't reduce your family tree to the 16, 32, etc persons that happen to be your direct lineage. It'll be much more rewarding at the end of the day.

[KGarrad]

I think it'd be cool to be able to trace one's geneology all the way back to Christ but maybe that's just a pipe dream?

First you need an answer to the question "Did Jesus have any children?".

[coombs]

I should look for Jesus on the 0020 census. 

Joking aside, genealogy does tend to get harder the further back you go but you never know how far back you can go and the 1600s is more than realistic. It depends on their occupation and the availability of records, sometimes if they were very poor in the 1600s and 1700s you may find a plethora of settlement certs and examinations.

[Wexflyer]

I should look for Jesus on the 0020 census. 

Well, there is the well known census of Judea in AD 1. Indeed "of the whole world'.

[Ayashi]

I'd say 1700s is realistic. I have some back to 1600s. In many cases it wasn't because I ran out of records, but ran out of differentiating information- for example, the birth of John Smith son of John Smith when there are multiple families at the same time in the same place, no mother's names, no occupations, no age on burials etc and no way to tell people apart. A lot of the time it is also easy to assume that someone was born near where they lived and there may be a handy matching christening when for all you know, bio ancestor may have moved quite a distance (one of mine was actually Scottish, as we found out from a note on one of the children's christenings) or may be from a nearby parish without surviving records. My mother has done DNA, which has helped back up the paperwork. I'm thinking I'm back about as far as I'm going to get and it is now a matter of focusing more on fleshing out the people involved where possible, even if in a generic "what did the average person live like at this time? What was going on in Britain while they were alive?" kind of way.

The further back you go, often the more sparse the information becomes on the records and, indeed, the more sparse the records become as it is less and less likely they've survived. You do get pockets of detailed information (thank you, Shute Barrington!) but you can also get writers who, for example, think a woman's surname isn't important on a marriage record because she has her husband's name now or who used old paperwork as a drink coaster.