One unusually well-documented example demonstrates the political and cultural porosity of prototypically international borders, along with the initial hesitance or inability of the operant monarchs to intervene. To quote an easy encapsulation, from a much more extensive and incisive secondary source: “On or about 1 November 1184, the county of Hainaut [ruled by Baldwin V, later VIII of Flanders] was invaded by the armies of [Baldwin’s brother-in-law] Philip Count of Flanders (1168-91), of Philip of Heinsberg, Archbishop of Cologne (1167-91), and of Godfrey III, Duke of Brabant (1142- 90), who was accompanied by his son Henry ([Duke] 1190-1235).” (France, pp. 97-8.) This map shows borders as of 1477, but just manages to include all of the main protagonists, from the archbishopric of Köln (and the neighboring imperial capital of Aachen) in the east, to the duchy of Brabant, and the counties of Hainaut and Flanders in the west. As of 1184, only Flanders was (peripherally) within the Capetian French political orbit. Hainaut and Brabant were ruled by Francophone dynasties under German (Staufen) suzereinty. (From Wikimedia Commons.) ...Improbably enough, it ended well for Baldwin, the count of Hainaut. A truce was brokered, then extended “under the aegis of [Philippe II, the] King of France.” By the following Spring, Baldwin was on the offensive, especially against Philip of Flanders. This time, Philippe II of France arrived with a substantial army against Philip of Flanders --demonstrating the pitch of mutual animosity between the king and his own nominal vassal. As France continues, “[a]lthough the two armies faced one another for three weeks, no battle resulted and in the end the Count of Flanders sued for a peace which greatly profited the French king and the Count of Hainaut” (99). On Philip of Flanders’ death in 1191, Baldwin assumed his county in right of his wife, Marguerite, Philip’s sister and heiress. (Cf. Cawley, Medieval Lands: https://fmg.ac/Projects/MedLands/FLANDERS, HAINAUT.htm#_Toc413913468 .) Right, some coins. With a couple of exceptions, these are petit deniers /mailles of the Low Countries, from the parts which were under Francophone rule. Flanders: Bruges. AR petit denier, Ghyssens ‘deuxiéme periode,’ c. 1180-1220. Obv. Soldier in mail hauberk advancing right, on foot (later variants show him spurred, suggesting a dismounted knight), brandishing a sword and carrying a large shield, of a type common to the later 12th century (transitioning from Norman ones seen on the Bayeux Tapestry.) Rev. Cross, decorated with pellets. (Ghyssens p. 107, 239; cf. De Wit 1254, p. 397 for a summary of Ghyssen’s chronology.) The shield shows half of a recognizable, distinctly early heraldic device: three chevrons. This corresponds to the arms of Hainaut, suggesting that this issue initially dates to the comital reign of Baldwin, 1191-1194. This 17th-century illustration shows Baldwin and his wife, Margaret of Flanders, with the chevrons of Hainaut above, and the lion of Flanders below. Flanders: Lille. Petit denier, Ghyssens 2nd period, c. 1180-1220. Obv. Triangle, pellet in center, annulets with pellets at each angle; fleurs de lis on each side. Rev. Cross; L/I/L/A in angles. (Ghyssens p. 115, 266; cf. 267, De Wit 1270, citing 266.) From here, that one has to do service for Philip of Alsace, the count of Flanders (1168-1191) who presided over the festivities. In a similar vein, the nearest I can get to Godfrey of Brabant is an issue of his son, Henri I, relatively late in his career. Henri I, Duke of Brabant 1190-1235. Petit denier, c. 1211-1235. Obv. Knight on horseback, brandishing sword (with indications of the stirrup and spur); quatrefoil below. (Inviting comparison to seals of the period, imitated in the 13th century on petit deniers of the Duchy of Lorraine.) (From 6 o’clock, retrograde, Flavian style; mostly off the flan: ) DV [...] X. Rev. 'Brabantine cross.' (Haeck p. 72, 43. The listing from the Elsen auction cites references to which I have no access (including another volume of Ghyssens: https://www.biddr.com/auctions/elsen/browse?a=595&l=612318 .) ...With Philipp von Heinsberg, Archbishop of Köln 1167-1191, there’s more mutual traction between the coins and the operant chronology. For a much better example, please (no, really) see @FitzNigel ’s avatar (this is the operant page, at least: https://www.cointalk.com/threads/ancient-forums-picture-the-poster.280392/page-42#post-4875701 ). ...Then there’s mine, of the 4th type, c. 1181-1190. (For the 4th type, this listing cites more references than I could: https://www.ma-shops.com/rittig/item.php?id=191227014 .) Meanwhile, there were the reigning monarchs, starting with Friedrich Barbarossa, from his Carolingian capital of Aachen (conveniently appropriated, along with the attendant Carolingian rhetoric. Sorry for the pics, along with the rhetorical excess regarding Friedrich --who was probably busy with his Italian wars; anyway, the whole episode seems to have been off his radar): ...And, just breezing along, here's one fun example of the French king, a coissue with the bishop of Laon, not far to the south of the fireworks. Philippe II (1180-1223), with Roger de Rosoi, Bishop of Laon (1174-1201). Rev. Roger, facing, mitred. (Full legend: ) +ROGERVS EPE[...scopus]. Obv. Philippe, facing, crowned. +PHILLIPVS RE[...x]. (Duplessy 184.) References The De Wit Collection of Medieval Coins. Part 1. Kuenker Auktion 121, 2007. Duplessy, Jean. Les Monnaies Françaises Royales. Tome I. 2nd ed. Paris, 1999. France, John. Western Warfare in the Age of the Crusades: 1000-1300. Ithaca: Cornell UP, 1999. Ghyssens, Joseph. Les Petits Deniers de Flandre des XIIe et XIIIe Siécles. Bruxelles 1971. Haeck, Aimé. De Brabantse kleine denieren van de dertiende eeu. Dilbeeek, Belgium 2016. ...For anyone who wanted to go deeper into the weeds, there’s this translation, with brilliant annotation and prefatory material. Gilbert of Mons. Chronicle of Hainaut. Laura Napran, editor and translator. Woodbridge, Suffolk, 2005.