[This book](http://books.google.com.sg/books?id=wuLrTJ0wtlMC&pg=PA302&lpg=PA302&dq=%22martyr%20for%22%20%22martyr%20to%22&source=bl&ots=cwI9lWF7-J&sig=JZDbOd15Wjoe5DWWwOAvhSaLAck&hl=en&sa=X&ei=dzUDU4rjKs2trAemm4H4Cg&redir_esc=y#v=onepage&q=%22martyr%20for%22%20%22martyr%20to%22&f=false) specifies the difference as:

> 
> **martyr for something**: smb. who is made to suffer severely for a cause
> 
> 
> **martyr to something**: smb. who is acutely inflicted by something
> 
> 
> 

Oxford dictionary also tells us this:

> 
> (martyr to) a constant sufferer from (an ailment):
> 
> 
> 

Other online dictionaries don't seem to explicitly specify a difference, though all example sentences for "martyr to" contain an ailment.

Yet, I've seen the usage "He/She is a martyr to his/her cause/country" a lot. In fact, google gives more hits to the "to" use than the "for" use.

> 
> **martyr to his cause**: 315,000 uses vs. **martyr for his cause**: 285,000 uses
> 
> 
> **martyr to his country**: 371,000 vs. **martyr for his country**: 266,000 uses
> 
> 
> 

So is there still a difference between the two in modern/current use? Is this a case of colloquial use being inconsistent with grammatically correct use? Is this a US vs UK issue? Help, please? Surprisingly google is not yielding even a single article discussing this usage.

ETA: Ngram comparisons that have now only increased my confusion. It seems "martyr to cause" is significantly more common is usage than "martyr for cause".
Diagrams for [Cause](https://books.google.com/ngrams/graph?content=martyr%20to%20his%20cause,martyr%20for%20his%20cause&case_insensitive=on&year_start=1800&year_end=2013&corpus=15&smoothing=1&share=&direct_url=t4;,martyr%20to%20his%20cause;,c0;,s0;;martyr%20to%20his%20cause;,c0;;Martyr%20to%20His%20Cause;,c0;.t1;,martyr%20for%20his%20cause;,c0) and [Country](https://books.google.com/ngrams/graph?content=martyr%20to%20his%20country,martyr%20for%20his%20country&case_insensitive=on&year_start=1800&year_end=2008&corpus=0&smoothing=1&share=&direct_url=t1;,martyr%20to%20his%20country;,c0;.t1;,martyr%20for%20his%20country;,c0)