IV. Participles

1. Although having lost control over much of eastern and southern Britain in the second half of the fifth century, the indigenous people, the Britons [k5: add a comma to close the apposition] Britons, retained extensive areas elsewhere in Britain until around 600.
   Having lost control over much of eastern and southern Britain in the second half of the fifth century, the indigenous Britons still retained extensive areas elsewhere until around 600.
2. Being from [k3: use a more natural expression for the origin of a society and culture] Originating in northern Germany and Denmark rather than the southern regions[k3: the comparison is vague and uneven] rather than farther south, Anglo-Saxon society and culture were less influenced by Rome and the Mediterranean than those of other Germanic peoples.
3. Being originated [k4: use the active form of the participle; “originate” is intransitive here] Originating on the North Sea coast of Europe [k5: add a comma after the introductory participial phrase] Europe, the main group was divided into [k3: this wording inaccurately presents three separate peoples as subdivisions of one group] the main groups were Angles, Saxons, and Jutes; tribal affiliations being loosed [k3: “loosed” means “released”; use the adjective “loose”] loose at this time, some tribes [k3: tribes cannot come from other groups; you mean individual migrants or settlers] some settlers also came from other Germanic groups.
4. France, Spain, and other areas speaking Romance languages, [k5: the comparison is incomplete and compares places with people] Unlike people in France, Spain, and other areas where Romance languages are spoken, the English use largely a Germanic language [k4: put “largely” before the adjective it modifies] a largely Germanic language.
   Unlike the Romance languages spoken in France, Spain, and elsewhere, English is largely Germanic.
5. Being [k2: make the concessive link with the main clause explicit] Although considered the greatest classic of Anglo-Saxon literature and probably composed in Northumbria in the first half of the eighth century, the epic poem Beowulf sets its story of heroic monster killing [k3: use a more natural and unambiguous expression] tale of heroic monster-slaying not among Anglo-Saxons but among the equally Germanic Danes.
6. Having been the founder of the royal house of Wessex and had a British name, Cerdic [k2: signal the contrast clearly; the British name, rather than the founding of Wessex, is the contrasting point + k4: the coordinated verbal forms are not parallel] Despite bearing a British name, Cerdic, the founder of the royal house of Wessex, is described by Anglo-Saxon writers centuries later as an Anglo-Saxon invader.
7. Involving fewer than a thousand people on either side, most battles were also fought on a low matériel level [k3: this is an unnatural collocation] with relatively little matériel.
8. Some of the most successful being able to take [k3: use the natural verb with “title”] claim the title of king, none were powerful enough to rule Britain or England as a whole.
   Despite some of the most successful leaders being able to claim the title of king, none were powerful enough to rule Britain or England as a whole.
9. The term being Brythoniaid, it [k5: avoid an awkward absolute construction followed by an unclear pronoun reference] Used at first, the term Brythoniaid was gradually replaced by Cymry.

Infinitival phrases

1. According to legend, this was not an invasion but a response to accept [k4: after the noun “response”, use “to” + noun rather than an infinitive] to an invitation by [k4: an invitation comes “from” a person] from a Celtic ruler named Vortigern.
   According to legend, the newcomers came not to invade but to accept an invitation from a Celtic ruler named Vortigern. [Use this version if the sentence must contain an infinitival phrase.]
2. One Anglo-Saxon poem, The Wanderer, uses the word “cities” to refer to Roman cities as the work of giants [k2: you have assigned the two expressions to the wrong elements + k3: “the work of giants” is a phrase, not a word] the phrase “the work of giants” to refer to Roman cities.
3. The archaeological evidence shows the principal weapon of ordinary Anglo-Saxon warriors to be the spear. [Correct: you have used the object + infinitive construction properly.]
4. The early Anglo-Saxons were [k3: people have a culture; they are not a culture] had a warrior culture to value [k4: this infinitive cannot postmodify “culture” with the intended meaning] that valued men for their courage and skill in battle, as reflected in Anglo-Saxon literature.
   The early Anglo-Saxons are known to have had a warrior culture that valued men for their courage and skill in battle, as reflected in their literature. [Use this version if the sentence must contain an infinitival phrase.]

Gerunds

1. On a demographic level, many Britons, particularly women, were assimilated into the Anglo-Saxon people by marrying, being enslaved, or adopting of [k4: do not use “of” after the gerund “adopting” when it has a direct object] adopting Anglo-Saxon culture.
2. Placing [k3: use the verb “classify” when assigning people to categories] Classifying some of the earliest figures in Anglo-Saxon history as either Anglo-Saxons or Britons is considered hard [k3: use the more natural adjective in this formal context] difficult.
3. The elite often preferred decorating the [k4: use a possessive determiner if you mean the elite’s own weapons] their weapons richly.
   The elite often preferred decorating their weapons lavishly.
4. There was no fading of Celtic culture, that [k4: use “which”, not “that”, in this non-defining relative clause] which remained strong in several areas of the old Roman province of Britannia.
   Celtic culture showed no signs of fading and remained strong in several areas of the former Roman province of Britannia.
5. Having poor internal communications meant that Wales’ political authority remained fragmented. [Correct: your gerund clause functions properly as the subject of “meant”.]