The company produced fine china in Ireland from 1953 to early 2000s.  
This was produced in Ireland.
They are still in business.
NO chips, No cracks, No crazing.  Looks excellent.  
About 9.5'' tall with lid.
Thanks for looking.
Please ask questions.  
Below is info on the pattern.  


Vintage Royal Tara 'Book of Kells' Fine Bone China Cup/Mug 8th Century Calligraphy Letter 'f' Galway, Republic of Ireland Beautiful Royal Tara Fine Bone China Irish Coffee/Tea Cup, from Galway, Republic of Ireland 
The pattern is from the 'BOOK OF KELLS', using the Celtic Illuminative Art design, and represents the letter"f" 
The calligraphy is intricate and beautiful, with vibrant colors. 
The 'Book of Kells' was created by Celtic Monks', ca 800 or slightly earlier.