Already Ottokar II, king of Bohemia, had splendid trade connections in all directions, also to the East.
https://en.wikipedia.org/wiki/Ottokar_II_of_Bohemia
He competed with Rudolf of Habsburg for the Empire after the interregnum 1272. Rudolf was chosen, cause he was the weaker alternative, the Kurfürsten (electors of the emperor) didn't like a strong emperor. A war between Ottokar and Rudolf resulted, Ottokar died at the battlefield (1278).
If the Mongols adapted playing cards in China, then there were many opportunities, how playing cards might have reached Europe. Naturally it's a longer way to reach a functioning production in Europe, getting some players to be interested and finally to realize a larger distribution, which by gambling use caused prohibitions. There might have been some smaller islands of playing cards use, which stranded or stayed hidden, long before 1367, the accepted date for Bern. Bern was visited by Charles IV in 1365, then on his way to Arles.
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The Trionfi card development at the Ferrarese court involved noble children and teenagers. Studying recently the conditions of the Austrian court, then we have an explosion of Northern Tarock use around 1750-55. Maria Theresia had totally 16 children, from which the oldest around 1755 had an age of 10-17.
Emperor Charles IV had ...
Charles was married four times. His first wife was Blanche of Valois, (1316–48), daughter of Charles, Count of Valois, and a half-sister of Philip VI of France. They had three children:
a son (b.1334), died young[8]
Margaret of Bohemia (1335 - 1349); married Louis I of Hungary.
Catherine of Bohemia (1342–95); married Rudolf IV of Austria and Otto V, Duke of Bavaria, Elector of Brandenburg.
He secondly married Anna of Bavaria, (1329–53), daughter of Rudolf II, Duke of Bavaria; they had one son:
Wenceslaus (1350–51).
His third wife was Anna von Schweidnitz, (1339–62), daughter of Henry II, Duke of Świdnica and Katharina of Anjou (daughter of Charles I Robert, King of Hungary), by whom he had three children:
Elisabeth of Bohemia (19 April 1358 – 4 September 1373); married Albert III of Austria.
Wenceslaus (1361–1419); later elected King of Germany (formally King of the Romans) and, on his father's death, became King of Bohemia (as Wenceslaus IV) and Emperor-elect of the Holy Roman Empire; married firstly to Joanna of Bavaria in 1370 and secondly to Sophia of Bavaria in 1389.
son (born and died 11 July 1362).
His fourth wife was Elizabeth of Pomerania, (1345 or 1347–1393), daughter of Duke Bogislaw V, Duke of Pomerania and Elisabeth of Poland, daughter of Casimir III of Poland. They had six children:
Anne of Bohemia (1366–94); married Richard II of England
Sigismund (1368–1437); later Holy Roman Emperor, King of Hungary and Bohemia, and Margrave of Brandenburg; married firstly Mary of Hungary in 1385, and secondly to Barbara of Cilli in 1405/1408.
John of Görlitz (1370–96); later Margrave of Moravia and Duke of Görlitz; married Richardis Catherine of Sweden. His only daughter and heiress was Duchess of Luxembourg.
Charles (13 March 1372 – 24 July 1373).
Margaret of Bohemia (1373–1410); married John III, Burgrave of Nuremberg.
Henry (1377–78)
The deciding factor is naturally Wenzel (oldest son), who had the major interest in this family. 1376 he was crowned as second king in Aachen as a 15-years-old boy, a large cavalcade of Bohemians accompanied the event. 1377 we have John of Rheinfelden observing a playing card revolution.
1441 we have Bianca Maria Visconti (15 years old) in Ferrara, likely accompanied mainly by two Ferrarese girls of the same age, Beatrice and Isotta.
The older children of Maria Theresia:
Maria Elisabeth (1737–1740)
Maria Anna (1738–1789), lebte später in Klagenfurt
Maria Karolina (1740–1741)
Joseph II. (1741–1790)
∞ 1760 Prinzessin Isabella von Bourbon-Parma, Tochter Herzog Philipps von Parma, Piacenza, Guastella
∞ 1765 Prinzessin Maria Josepha von Bayern, Tochter Kaiser Karls VII.
Maria Christina (1742–1798) ∞ 1766 Herzog Albert Kasimir von Sachsen-Teschen
Maria Elisabeth (1743–1808), Äbtissin in Innsbruck
Karl Joseph (1745–1761), Erzherzog
Maria Amalia (1746–1804) ∞ 1769 Herzog Ferdinand von Parma, Sohn Herzog Philipps von Parma, Piacenza, Guastella
Leopold II. (1747–1792) ∞ 1765 Infantin Maria Ludovica von Spanien a.d. Haus Bourbon-Anjou, Tochter König Karls III.
...
The deciding signal for the Austrian court and its playing card use are the production of playing card books:
quoted from HANS JOACHIM ALSCHER
http://www.tarock.info/Alscher
Regeln bey dem Taroc-Spiele (Leipzig 1754)
Älteste Tarockregeln in deutscher Sprache, auch abgedruckt in "Palamedes redivivus" Leipzig 1755
Die beste und neueste Art, das in den vornehmsten Gesellschaften heutiges Tages so beliebte Taroc-Spiel, so wol in drey Personen zum König als in vier wirklichen Personen mit zweyerley Karten recht und wohl zu spielen, nebst einigen Betrachtungen über dieses Spiel und einem Anhang von ganz neuerfundenen Kartenkünsten (Wien und Nürnberg 1756)
Ältestes österreichisches bzw. ältestes Wiener Tarockbuch
see also:
viewtopic.php?f=11&t=622&start=14
The deciding prince, Joseph II, was (again) 15 years old in 1756.
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The natural context is naturally, that emperors, kings and other high rulers promoted games, when their own children had the right age to play the games. Cause an engagement of emperors, kings and other high rulers naturally influenced the general games market, this caused "games fashions" for everybody.
Lorenzo de Medici likely should be also noted in this context. The younger Louis XIV (5 years old and already king of France) caused the development of a long running tradition of teaching games on cards.
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If one believes the researcher Hübsch, then playing cards were already a longer time in Prague. But there was no direct promotion from the side of Charles IV. This might have been different in 1376.
