The term is also sometimes employed by writers who want to avoid terms such as "royal mistress", or "friend", "companion" or "lover" of either sex. Several favourites had sexual relations with the monarch (or the monarch's spouse), but the feelings of the monarch for the favourite covered the full gamut from a simple faith in the favourite's abilities to various degrees of emotional affection and dependence, sometimes even sexual infatuation.
The term has an inbuilt element of disapproval and is defined by the Oxford English Dictionary as "One who stands unduly high in the favour of a prince", citing William Shakespeare: "Like favourites/ Made proud by Princes".
Favourites inevitably tended to incur the envy and loathing of the rest of the nobility, and monarchs were sometimes obliged by political pressure to dismiss or execute them; in the Middle Ages nobles often rebelled in order to seize and kill a favourite. Too close a relationship between monarch and favourite was seen as a breach of the natural order and hierarchy of society. Since many favourites had flamboyant "over-reaching" personalities, they often led the way to their own downfall with their rash behaviour. As the opinions of the gentry and bourgeoisie grew in importance, they too often strongly disliked favourites. Dislike from all classes could be especially intense in the case of favourites who were elevated from humble, or at least minor, backgrounds by royal favour. Titles and estates were usually given lavishly to favourites, who were compared to mushrooms because they sprang up suddenly overnight, from a bed of excrement. The King's favourite Piers Gaveston is a "night-grown mushrump" (mushroom) to his enemies in Christopher Marlowe's Edward II.
Their falls could be even more sudden, but after about 1650, executions tended to give way to quiet retirement. Favourites who came from the higher nobility, such as Leicester, Lerma, Olivares, and Oxenstierna, were often less resented and lasted longer. Successful minister-favourites also usually needed networks of their own favourites and relatives to help them carry out the work of government – Richelieu had his "créatures" and Olivares his "hechuras". Oxenstierna and William Cecil, who both died in office, successfully trained their sons to succeed them.
The favourite can often not be easily distinguished from the successful royal administrator, who at the top of the tree certainly needed the favour of the monarch, but the term is generally used of those who first came into contact with the monarch through the social life of the court, rather than the business of politics or administration. Figures like William Cecil and Jean-Baptiste Colbert, whose accelerated rise through the administrative ranks owed much to their personal relations with the monarch, but who did not attempt to behave like grandees of the nobility, were also often successful. Elizabeth I had Cecil as Secretary of State and later Lord High Treasurer from the time she ascended the throne in 1558 until his death 40 years later. She had more colourful relationships with several courtiers; the most lasting and intimate one was with Robert Dudley, Earl of Leicester, who was also a leading politician. Only in her last decade was the position of the Cecils, father and son, challenged by Robert Devereux, 2nd Earl of Essex, when he fatally attempted a coup against the younger Cecil.