Ealhmund, Under King Of Kent - Bad math

My 32nd Great Grandfather - another learning curve on historical events during his time. Thanks Alex, we have curators who are "as sharp as a tack!" : )

Well, i got as far as 1+1 does not = 3
After that i'm looking for help :)

Google search gives - Born: 745 AD, Wessex Died: 780 AD

But as the only contemporary evidence of him is apparently dated 784 the Google dates can't be right either

So 1+1 does not =4 either

Medlands gives his death date as "after 784, maybe after 801" and gives his son a DOB "769/80"
(so 1+1= a number other than 1)

c.758 is a popular DOB online but it just looks like a circular pasting, as i said initially 758 is too late if his so was born 769 but not too bad if Jnr is born 780. BUT considering that according to the Chronicle, Ecgberht was expelled from England in 789 by King Beorhtric after he unsuccessfully challenged Beorhtric's succession then a DOB of 780 seems unlikely (my 9 year old is a bit bossy but not challenging any monarchs at this point!)

birth dates for these people are non existent so the values should be locked as blank

sounds good but technically i don't think it's possible to lock as blank?
If we delete then the software will estimate a range based on the nearest other profile with a DOB and you risk ending up with some ridiculous ranges.

yes you can lock it as blank. e.g. Elesa

Elesa is locked as blank but displays as a date range based on nearby family.

I blanked Ealhmund's DOB and software gave a range of "estimated between 737 and 779"
I am not sure if it is being influenced by his fathers DOB or son's or both. Either way 737 is too early compared to his father's displayed DOB and 779 is too late knowing that he was king in 784.
I have reverted to previous DOB for time being even though it is doubtful.

Both Ecgberht ([769/80] and Æthelwulf [795/810] have estimated DOBs on Medlands which is uncommon for this era and Cawley favours the earlier date forÆthelwulf and by inference the earlier date for Ecgberht. I imagine the earlier generations DOB are all worked backwards from these two and the variation appears based on the method of calculation and start point.

if we blank all the unsourced dates then it should make the estimates less crazy?

Not sure, "less crazy" :)

temporary placeholder gets a Birth: estimated between 704 and 764 which is based on his son sonny boy having DOB c769

So it depends on your definition of crazy.
764 works fine with known reign of 784 but 704 is a bit of a stretch given same.