You need to identify a person whom we shall call Z. Despite the title of the cache, Z's name will probably not be familiar to you, although they were considered sufficiently important that you can read their obituary on the web site of a national newspaper.
Even though Z may not be considered famous as an individual, they were a member of a group whose name, and something of what they did, will be well known to many. However Z did not join this group until after the event that made them famous, and which gave them their name.
To help you find who Z was, you may find it helpful to identify two 'sisters', who we shall call X and Y. X is resident in the UK and is often seen in public. On the other hand, Y lives abroad but visited the UK in the summer of 2014 and was frequently seen together with X. They even visited Surrey. During their busy schedule they managed to fit in a flying visit to a third sister, W, who is less active than the other two. A bit of 'blue-sky thinking' may be needed to identify the sisters.
Hopefully you will now have worked out who W, X and Y are. If you research the recent history of X (since 2012 but prior to 2017) you should discover the identity of Z.
To find the cache, you will need to answer the following questions:
A = day of month (1-31) that Z was born
B = month (1-12) that Z died
C = total number of letters in the name of Z's employer at the time of their retirement
D = the number that forms part of X's current nickname
E = the number of letters in Y's nickname
You will not be surprised to find that W also has a nickname. F is the total number of letters in the two words of this nickname.
G = the number of letters in the surname of the author of the first book about the group to which Z belonged
H = the age of Z when they died
The cache can be found at N51 P W000 Q where:
P*1000 = (B*C*H) - (4*H) - (A+G+E)
Q*1000 = (A*B*C*G) +((A+G)*H) + (A*(D+F)) + (2*C)
