Beginning with the Lithuanian Grand Duke Jogaila ( Władysław II Jagiełło ), the Jagiellon dynasty ( 1386 – 1572 ) formed the Polish – Lithuanian union.

In 1206 Henry and his cousin Duke Władysław III Spindleshanks of Greater Poland agreed to swap the Silesian Lubusz Land against the Kalisz region, which met with fierce protest by Władysław's III nephew Władysław Odonic.

When Henry went to Gąsawa in 1227 to meet his Piast cousins, he narrowly saved his life, while High Duke Leszek I the White was killed by the men of the Pomerelian Duke Swietopelk II, instigated by Władysław Odonic.

The next year Henry's ally Władysław III Spindleshanks succeeded Leszek I as High Duke ; however as he was still contested by his nephew in Greater Poland, he made Henry his governor at Kraków, whereby the Silesian duke once again became entangled into the dispute over the Seniorate Province.

Her actions promoted the reign of her husband: Upon the death of the Polish High Duke Władysław III Spindleshanks in 1231, Henry also became Duke of Greater Poland and the next year prevailed as High Duke at Kraków.

This union was contracted in connection with the Ascanian efforts to support the Junior Dukes in opposition to King Conrad III of Germany, who supported the deposed High Duke Władysław II as legal ruler of Poland.

* Władysław III Spindleshanks ( 1165 – 1231 ), Duke of Poland

* Władysław Vasa of Poland ( 1595 – 1648 ), Polish Prince, self-proclaimed Grand Duke of Moscow, and future King of the Polish-Lithuanian Commonwealth

* Elisabeth of Opole ( 1360 – 74 ), daughter of Duke Władysław Opolczyk, in 1372.

* Agnes of Opole ( d. 1413 ), daughter of Duke Bolesław ( Bolko ) II of Opole and sister of Duke Władysław, in 1374.

He began to follow a policy which was more independent from Bohemia, including in respect to friendly relations with his Upper Silesian cousin Duke Władysław of Opole and also with duke Przemysł II of Greater Poland.

At that time, he also made an alliance with Duke Władysław of Opole, who promised to help Henry IV with the condition that his daughter ( perhaps called Constance ), who had recently married Henry IV, was crowned with him as Polish queen if he would obtain the royal investiture.

Henry IV's major contenders for the Krakow throne were Leszek II's half-brother Władysław I the Elbow-high and Duke Bolesław II of Płock, who counted on the support of the Lesser Poland nobility.

The battle ended with a victory for the Masovia-Kuyavia coalition ; from two of Henry IV's allies, Duke Przemko of Ścinawa was killed in the battle, and Duke Bolko I of Opole was seriously injured and captured by Władysław I the Elbow-high.

Around March 1280, Henry IV married firstly with the daughter of Duke Władysław of Opole ( b. ca.

** Władysław II Jagiello succeeds his father, Algirdas, as Grand Duke of Lithuania.

This bloody conflict was eventually brought to a temporary halt in 1392 with the Treaty of Ostrów, by which Władysław handed over the government of Lithuania to his cousin in exchange for peace: Vytautas was to rule Lithuania as the Grand Duke ( magnus dux ) until his death, under the overlordship of the Supreme Duke ( dux supremus ) in the person of the Polish monarch.

Serving initially in the household of Duke Władysław I Herman of Poland, he entered the service of the Emperor Henry IV in 1090 and was appointed Chancellor of the Holy Roman Empire in 1101.

* 1713 – Charles I, Duke of Brunswick-Wolfenbüttel ( d. 1780 )

* 1557 – Frederick I, Duke of Württemberg ( d. 1608 )

* Albert I, Duke of Brunswick-Lüneburg ( 1236 – 1279 ) second Duke of Brunswick-Lüneburg

* Albert I, Duke of Prussia ( 1490 – 1568 ), first Duke of Prussia

Albert the Bear (; c. 1100 – 18 November 1170 ) was the first Margrave of Brandenburg ( as Albert I ) from 1157 to his death and was briefly Duke of Saxony between 1138 and 1142.

Albert was a loyal vassal of his relation, Lothar I, Duke of Saxony, from whom, about 1123, he received the Margraviate of Lusatia, to the east ; after Lothar became King of the Germans, he accompanied him on a disastrous expedition to Bohemia in 1126, when he suffered a short imprisonment.

Albert was chosen as his successor early in 1511 in the hope that his relationship to his maternal uncle, Sigismund I the Old, Grand Duke of Lithuania and King of Poland, would facilitate a settlement of the disputes over eastern Prussia, which had been held by the Order under Polish suzerainty since the Second Peace of Thorn ( 1466 ).

He married secondly to Anna Maria ( 1532 – 20 March 1568 ), daughter of Eric I, Duke of Brunswick-Lüneburg, in 1550.

He was elected Grand Duke of Lithuania on the death of his father ( 1492 ), and King of Poland on the death of his brother John I Albert ( 1501 ).

By the age of twenty, Ferdinando I, Duke of Mantua, began commissioning works from him, and he was also employed by local jewelers for figurative designs.

* Afonso, 1st Duke of Braganza, son of John I of Portugal.

* Afonso, Duke of Porto, son of Louis I of Portugal.

* Alfonso I d ' Este, Duke of Ferrara during the time of the War of the League of Cambrai.

* Alfonso I d ' Este, Duke of Ferrara ( 1476 – 1534 )

In the summer of 1214, Andrew had a meeting with Grand Duke Leszek I of Poland and they agreed that they would divide the Principality of Halych between Hungary and Poland.

However, Andrew denied to transfer the agreed territories to Duke Leszek I who made an alliance with Prince Mstilav of Novgorod and they drove away Andrew's troops from the principality.

Andronikos III was first married, in 1318, with Irene of Brunswick, daughter of Henry I, Duke of Brunswick-Lüneburg ; she died in 1324.

This provision was repealed in 1716, at the request of George I, who was also the Elector of Hanover and Duke of Brunswick-Lüneburg of the Holy Roman Empire, and so frequently needed and wanted to stay in Hanover.

* 1578 – Duel of the Mignons claims the lives of two favourites of Henry III of France and two favorites of Henry I, Duke of Guise.

* 1290 – Leopold I, Duke of Austria ( d. 1326 )

* 1574 – Cosimo I de ' Medici, Grand Duke of Tuscany ( b. 1519 )

An accord was made between him and the Bohemian Duke Borivoj I ( reigned 870-95 ); Bohemia was thus freed from the dangers of invasion.

In 1600 he was called to Parma by Duke Ranuccio I Farnese to began the decoration of the Palazzo del Giardino, but he died before it was finished.