Lost on creating a query for this scenario

Lost on creating a query for this scenario

Here is a simplified version of the table structure.
Employee
(
ID GUID NOT NULL
OldID GUID NULL
Name VARCHAR(50) NOT NULL
CreationDate DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
)
It contains employee information as well as any changes been made to
employee attributes. This way we can get a complete audit of changes been
made. When OldID is NULL, that basically mean the latest data. Here is an
example, I am using integer values for identifier to make this example
easier to understand.
ID OldId Name CreationDate
13 NULL John 15-July-2013
12 13 John1 14-July-2013
11 12 John2 13-July-2013
10 11 John3 12-July-2013
121 NULL Smith 15-July-2013
So there are two employees (as for these two cases OldId is null ) and
their latest names are john and Smith. I need to get the earliest name of
same employee and not sure how to query this data to get earliest name
also (John3) Any help will be highly appreciated.