This paper develops a new theoretical framework to describe the long diachrony of speech acts. Such an undertaking requires a careful reconsideration of some of the basic properties of the nature of speech acts. It requires a clear differentiation between the functional profile, or illocutionary potential, of a speech act, the range of expressions that are typically used to perform it, and the metacommunicative expressions that are used to talk about it. It also requires a clear understanding of the integrity of the speech act in order to make it comparable across different time periods. It is suggested that the diachronic development of speech acts is both a gradual process with limited short-term effects that – over a long period – lead to more substantial differences and a process of attenuation, i.e. a progressive weakening of its illocutionary force. As an example, this paper traces the long diachrony of apologies in the history of the English language, from Old English up to Present-day English. Apologies originate in Old English penitential acts and confessions to God which in the course of time underwent a process of attenuation that first turned them into secularized appeals to a human addressee for forgiveness, subsequently to expressions of regret and eventually to speech acts that are often no more than a token acknowledgement of some minor infraction. The final section gives an outline of how this new theoretical framework of speech act attenuation can be applied to other speech acts, such as promises and greetings.