It is a familiar enough phrase, but what does it really mean and where does it come from?
To answer the second question first – it’s one of many expressions first coined by William Shakespeare. It comes from Act 5 Scene 3 of King Richard III. Richard is preparing to do battle against Henry Tudor at Bosworth and is considering the relative strength of the opposing forces. He is told that Henry’s army amounts to “six or seven thousand” and he replies:
“Why our battalia trebles that account!
Besides, the King’s name is a tower of strength,
Which they upon the adverse faction want.”
In other words, men who fight for the rightful king will be stronger in battle than those who do not – an interesting and somewhat flawed concept, one might imagine.
Shakespeare’s source for the expression might well be the Old Testament, namely Proverbs 18, verse 10:
“The name of the Lord is a strong tower: the righteous runneth into it, and is safe.”
We know that Shakespeare – writing during the reign of Tudor Queen Elizabeth I – was convinced that Richard III was a villain who deserved everything he got. It is therefore entirely possible that when he made Richard misquote the Book of Proverbs he was implying that Richard was committing a form of blasphemy – the “name of the Lord” has become “the King’s name”. One wonders how many members of his audience at The Globe Theatre would have picked this up?
The misquotation from “a strong tower” to “a tower of strength” might imply that Richard was using empty words. The image of people running into a strongly built tower for protection is clear enough, but the literal meaning of “a tower built from strength” does not make a lot of sense.
On the other hand, Shakespeare might simply have used those words for the purpose of scansion in a poetic line and considered that “a strong tower” is what Richard was implying.
Even so, it is quite a leap from the notion of people relying on the name of God as a protection from evil to soldiers gaining strength in battle because they know that they are fighting for a King.