Including the father of the only heir I'll ever have.

I'm his only heir - but that doesn't mean anything.

The only heir was her mother, who lived in England.

Her husband was the only heir to the title, I believe.

Also, so far as the books showed, George was the only possible heir to the old man.

However, as the only heir, she is less concerned with her father's businesses.

If they decide to take her to an institution, Pauline will be the only heir.

"You'll give me the only heir I want," he said.

It indicates that he is the only heir to the throne.

After all, the Baron couldn't risk the life of his only trained heir.