As King Alfred the Great commanded in the ninth century: ‘If anyone plot against the king’s life, of himself, or by harbouring of exiles, or of his men; let him be liable with his life and in all that he has’. Laws of King Alfred and Ine, Early English Text Society. Publications Original Series 208; (ed.), Flower/Smith, pp. 13–42.

In the Carolingian and post Carolingian world methods used by authorities to carry out these sentences varied depending upon the context but hanging and beheading were certainly two of the most common. Esther Cohen has observed that there were however several alternative forms of execution. She cites the execution of those who had assassinated Charles the Good in the early twelfth century; an instance which ended with some individuals be "precipitated" from a rooftop to their deaths while others were crucified on a gallows with their limbs stretched out to provoke suffocation. Esther Cohen, "The Meaning of the Head in High Medieval Culture" in Disembodied Heads in Medieval and Early Modern Culture ed. Catrien Santing, Barbara Baert, Anita Traninger (Brill, 2013), 65.

However there were some notable regional differences to the uniform use of capital punishment in the early and high medieval periods that are of interest to scholars of Anglo-Norman history.

In the Scandinavian context the use of capital punishment has traditionally been very complicated. Curiously there was a significant taboo against execution based on how lords perceived kinship bonds that went on to at least notionally inform Norman customs. This is not to say for a moment that political enemies were never executed; naturally some were. The point is rather that there was a particular interest in finding alternative methods of disposing of such persons through the use of selective violence against specific and culturally significant features of the body.

As van Eckels writes, "Cultural anthropology provides a plausible explanation: the widespread taboo against killing relatives. Scandinavian kingdoms of the high Middle Ages were inhabited by a limited number of free families, all bound to each other and to the royal dynasty by a dense network of marriage alliances. Not only did a Scandinavian nobleman know all of his fellow aristocrats but he could also safely assume that they all were in one way or another his kin." Klaus van Eckels, "Gendered Violence: Castration and Blinding as Punishment for Treason in Normandy and Anglo‐Norman England" Gender and History, 16 no. 3 (November, 2004), 593.

In the tenth century with the establishment of Scandinavian settlements in Northern France these same cultural attitudes were transmitted to early Norman communities. Remarkably, these customs would persist into the eleventh century and even came to influence the specific legislation surrounding treason and execution instituted by William the Conqueror in post-Conquest England.

Following his defeat of Harald Godwinson and institution of Norman hegemony William broke from Anglo-Saxon precedent which had recognized the death penalty and decreed: "I also forbid that anyone shall be slain or hanged for any fault, but let his eyes be put out and let him be castrated." Die Gesetze der Angelsachsen (ed.), Liebermann, vol. 1, pp. 486–488, p. 488, with vol. 3, pp. 277–279 [Rerum Britannicarum Medii Aevi Scriptores (‘Rolls Series’) 51.2, pp. CI ff]: 10. Interdico etiam, ne quis occidatur aus suspendatur pro aliqua culpa, sed eruantur oculi et testiculi abscindantur; tr: English Historical Documents, vol. 2, p. 431 ff.

This is quite an extraordinary pronouncement, and perhaps counterintuitive to what we might expect from a person like William who has responsible for such extraordinary bloodshed in his violent takeover of the country. Yet, once again we must recognize that this law was not necessarily followed simply because we have evidence of its decree. Indeed William continued to execute enemies during his reign; however that is not necessarily the point. An important thing to note here is that this legislation has offered Anglo-Norman kings the possibility of choice in their negotiation of these kinds of cases and found other more dynamic ways of wielding violence beyond mere capital punishment.

As van Eckels writes, "In Anglo-Norman England, the Anglo-Saxon death penalty was not abolished, but complemented by an equivalent, which spared a convicted man’s life, but destroyed the very basis of his social existence by depriving him of two vital parts of his body: his eyes and his testicles." Klaus van Eickels, "Gendered Violence" 589.

The use of castration and its powerful symbolic value can be seen in the emasculation and mutilation of Simon de Montfort's body after the Battle of Evesham, and the public castration of Hugh Despenser during his execution in 1326.

The targeting of a convicted prisoner's genitals was a traumatic assault on their entire gender identity. Castration has a long history in Christian society and has been discussed by scholars like Jo Ann McNamara with great erudition. Some have even come to question whether men who renounce sexual behaviour, both performatively through celibacy and physically through castration, were viewed as a third gender in medieval society.

From the voluntary actions of Origen to the assault on Peter Abelard, there are varied ways of interpreting the integrity of an individuals male-ness in the aftermath of such violence. On one hand it could allow a person to transcend the temptations of lust and ascend to new heights of spiritual contemplation. On the other hand for a layman convicted of treason, a sentence of castration eradicated any future for contributing further to their dynastic line, and it rendered them unable to perform sexually, one of the most core constitutive behaviours of male identity.

Thus in the Anglo-Norman world the opening up of corporeal punishment of treason to alternative forms of violence against the male body had interesting gendered and political valences. I hope that somewhat answered your question, although I apologize for limiting my focus to a more narrow focus as it is a very large topic.