The phrase "an old king" is correct and usable in written English.
You can use it when referring to a king who is advanced in age, often in a narrative or descriptive context.
Example: "In the heart of the kingdom, there lived an old king who had ruled for decades, his wisdom unmatched by any other."
Alternatives: "an aged monarch" or "a senior ruler."
He couldn't remember the title but knew it was about an old king who had three daughters".
She heard him tell a fairytale about an old king who wanted to marry a young princess who would kill him.
A dramatization of William Shakespeare's play in which tragedy occurs when an old king prematurely divides his kingdom between his daughters in the vain hope that they will care for him in his old age.
"With a decidedly young population, it seems to me that having a young king instead of an old king will be popular," Walter Cutler, a former U.S. Ambassador to Saudi Arabia, told me.
That was a young king who was encased in ritual and who had to learn about human suffering: his Lear is an old king who has to undergo a similar moral journey in which he acquires sanity via madness.
After meeting an old king who offers him some advice and some magic stones, Santiago embarks on his journey to cross the Mediterranean and the Sahara to find his treasure and accomplish his Personal Legend (a concept equivalent to our purpose in life).
Am I now becoming this person, a commercial animal?" In tournaments, he remains a bully, a greedy old king.
It's odd for an art form which sees its participants routinely pretend to be a mad old king on a blasted heath or a mass murderer, or a woman who realises that her marriage and life are a sham.
The best they can offer is a way to fill the time before death, and a method of protesting its coming that is as vain, as compromised and as heroic as a mad old king howling against a storm.
The villain of the piece is Noah Cross (John Huston), a corroded old king who fathers a child by his daughter and merrily boasts that a powerful man can do whatever he likes.
His official biographer, Harold Nicolson, later despaired of George's time as Duke of York, writing: "He may be all right as a young midshipman and a wise old king, but when he was Duke of York ... he did nothing at all but kill [i.e. shoot] animals and stick in stamps".
