Frederick William I, King of Prussia, and George II, King of England, though cousins and brothers-in-law, were never on good terms with each other. Frederick William resented George's marriage to Caroline, as he had once been a suitor for her hand. Bad-tempered and vicious, he often beat his wife, for which George despised him, even though he did not particularly like the Queen of Prussia, his own sister. Both kings gave each other contemptuous nicknames. George was "the comedian", while Frederick William was "the drill sergeant".
When Frederick William was on his deathbed, he asked the pastor whether it was necessary to forgive all his enemies. On receiving the answer "Yes", he said to the queen, "Dorothy, write to your brother that I forgive him all the evil he has done me, but wait till I am dead first."
普魯士國王腓特烈．威廉一世是英國國王喬治二世妹夫，二人也是表兄弟，但彼此向來不睦。腓特烈．威廉恨喬治娶了他曾經追求的凱羅蘭。喬治雖然無愛於其親妹，即普魯士王后，但見腓特烈．威廉脾氣暴躁，性情兇惡，常打妻子，也看他不起。兩個國王都輕蔑相稱：喬治是「滑稽伶人」，腓特烈．威廉則是「士卒教官」。
腓特烈．威廉臨終時，問牧師要不要寬恕所有敵人，聽到牧師說要寬恕，就跟妻子說：「朶勒絲，寫信給令兄，說我寬恕了他對我做的種種惡事。不過，待我死後，才寫這封信吧。」