* Descendant lines

[d1anep]

My grandfather and grandmother were first cousins, so had the same surnames, and I find that if I put in both their descendant lines, my family (and my descendants) appear twice in the family tree. Do you suggest that I just follow the line down from only my grandfather or leave it as it is?

In the same generation there were also two more sets of first cousins that married, so the same thing applies. It is beginning to look very repetitious.

[tatewise]

I think I understand what you are describing.
Your grandfather & grandmother are married and are also 1st cousins.
i.e. One of each of their parents are siblings.

I imagine you have only actually entered one line of descent.
i.e. Your father (or mother) is their child.

So I am not sure what you mean by: "I put in both their descendant lines".

There can be some repetition in some Diagrams but by closing branches this can be made minimal.

What tree Diagram types are you using, and who is the Diagram Root person?

[LornaCraig]

I think the default setting in Diagram Options is to Check for Duplicates and, within the options for that, to Hide duplicated family branches (when diagram is first built). So if you are seeing the duplicate branches in a diagram either you have changed the installation settings or you really have entered your grandparents' descendants twice (in which case they have different IDs in the two lines and will not be recognised as duplicates by FH). You only need to enter their descendants once, and use the Diagram Options to control the display. You might find this extract from the Help files useful:

[d1anep]

You are correct in that my grandfather's and grandmother's parents were siblings. I am the root person and I'm using All Relatives diagram.

However, I've now enabled check for duplicates and hidden duplicated branches. The diagram looks so much better and is not so bulky now. Thanks.