Question: Targe (from Old Franconian *"targa " "shield", Proto-Germanic *"targo " "border") was a general word for shield in late Old English, its diminutive, "target", came to mean an object to be aimed at in the 18th century, Frankish,  Old Franconian or Old Frankish was the West Germanic language spoken by the Franks between which type span?

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History of the Dutch language: Dutch is a West Germanic language, that originated from the Old Frankish dialects.

German language: German ("Deutsch" ] ) is a West Germanic language that is mainly spoken in Central Europe.  It is the most widely spoken and (co-) official language in Germany, Austria, Switzerland, South Tyrol (Italy), the German-speaking Community of Belgium, and Liechtenstein.  It is also one of the three official languages of Luxembourg.  The languages which are most similar to German are the other members of the West Germanic language branch: Afrikaans, Dutch, English, the Frisian languages, Low German/Low Saxon, Luxembourgish, and Yiddish.  German is the second most widely spoken Germanic language, after English.

Proto-Norse language: Proto-Norse (also called Proto-Scandinavian, Primitive Norse, Proto-Nordic, Ancient Nordic, Ancient Scandinavian, Old Nordic, Old Scandinavian, Proto-North Germanic, North Proto-Germanic or Common Scandinavian) was an Indo-European language spoken in Scandinavia that is thought to have evolved as a northern dialect of Proto-Germanic in the first centuries CE.  It is the earliest stage of a characteristically North Germanic language, and the language attested in the oldest Scandinavian Elder Futhark inscriptions, spoken around from the 2nd to 8th centuries (corresponding to the late Roman Iron Age and the Germanic Iron Age).  It evolved into the dialects of Old Norse at the beginning of the Viking Age in about 800, which later themselves evolved into modern North Germanic languages.

Thing (assembly): A thing was the governing assembly of a northern Germanic society, made up of the free people of the community presided over by lawspeakers.  The word appears in Old Norse, Old English, and modern Icelandic as "þing" (where "þ" is pronounced like unvoiced "th" /θ/), in Middle English (as in modern English), Old Saxon, Old Dutch, and Old Frisian as "thing", in Old High German, Middle High German, Pennsylvania Dutch, Middle Dutch, modern Dutch, and Afrikaans as "ding" and modern German as "Ding", and in modern Norwegian, Danish, Swedish, Faroese, Gutnish, and Norn as "ting", all from a reconstructed Proto-Germanic neuter "*þingą"; the word is the same as the more common English word "thing", both having at their heart the basic meaning of "an assemblage, a coming together of parts"—in the one case, an "assembly" or "meeting", in the other, an "entity", "object", or "thing".  The meeting-place of a thing was called a "thingstead" (Old English "þingstede") or "thingstow" (Old English "þingstōw").

Targe: Targe (from Old Franconian *"targa " "shield", Proto-Germanic *"targo " "border") was a general word for shield in late Old English.  Its diminutive, "target", came to mean an object to be aimed at in the 18th century.

Franconian languages: Franconian (German: "Fränkisch" ; Dutch: "Frankisch" ) includes a number of West Germanic languages and dialects possibly derived from the languages and dialects originally spoken by the Franks from their ethnogenesis in the 3rd century AD.  The languages that evolved in the northern and eastern lands of Francia included Low Franconian, of which present-day Dutch is the primary member, the West Central German Rhine Franconian and Central Franconian dialects (including Luxembourgish), as well as transitional High Franconian German dialects.  Linguists have different views about whether these languages and dialects have descended from a single Franconian proto-language, also known as Istvaeonic.

Old Saxon: Old Saxon, also known as Old Low German, was a Germanic language and the earliest recorded form of Low German (spoken nowadays in Northern Germany, the northeastern Netherlands, southern Denmark, the Americas and parts of Eastern Europe).  It is a West Germanic language, closely related to the Anglo-Frisian languages.  It has been documented from the 8th century until the 12th century, when it gradually evolved into Middle Low German.  It was spoken throughout modern northwestern Germany, primarily in the coastal regions and in the eastern Netherlands by Saxons, a Germanic tribe who inhabited the region of Saxony.  It partially shares Anglo-Frisian's (Old Frisian, Old English) Ingvaeonic nasal spirant law which sets it apart from Low Franconian and Irminonic languages, such as Dutch, Luxembourgish and German.

Frankish language: Frankish (reconstructed Frankish: "*Frenkisk"), Old Franconian or Old Frankish was the West Germanic language spoken by the Franks between the 4th and 8th century.  The language itself is poorly attested, but it gave rise to numerous loanwords in Old French.  Old Dutch is the term for the Old Franconian dialects spoken in the Low Countries, ie.  in present-day Belgium, in the present Netherlands and Western parts of today's Germany until about the 12th century when it evolved into Middle Dutch.

Low Franconian languages: Low Franconian, Low Frankish (Dutch: "Nederfrankisch" , German: "Niederfränkisch" , French: "Bas Francique" ) are a group of several West Germanic languages spoken in the Netherlands, northern Belgium (Flanders), in the Nord department of France, in western Germany (Lower Rhine), as well as in Suriname, South Africa and Namibia that originally descended from Old Frankish.

Bourgault: Bourgault (] ); is a surname derived from Old French but ultimately of Germanic French origin .  "Bourg" is from the Frankish *burg meaning town, fortress, or castle and "ault" (-aud) from the Frankish *wald meaning power, mastery, or rule.  Philologically, a plurality of Frankish (Franconian) words with the phoneme "w" were changed to gu/ga/gau while developing into nascent old French (e.g. Frankish *werra "war"= "guerre" in Old French, *want "gauntlet"= "gant", and *walha "foreigner/Celt"= "gaulois").  See: Gauthier.  Thus, the name means roughly "master of fortification," indicating a position along the lines of a castellan or burgrave.  The toponymic "gau" may be significant by dint of the historiographical connotations of the name's meaning.  Archaic variants and cognates of the name, used then as an occupational given name, are attested to as early as the 6th century and are found in Fredegar's chronicle although the validity of this source, notwithstanding its primary nature, is often called into question.  Therein, one Burgoald was a strongman under King Guntram in the area of Chalon.

Supporting paragraphs: Targe Frankish language
Answer: 4th and 8th century