At the time of the 14th century, Lithuania was continuously invaded by the State of the Teutonic Order. The future King of England Henry IV (then Henry Bolingbroke) spent a full year of 1390 supporting the unsuccessful siege of Vilnius by Teutonic Knights with his 300 fellow knights. During this campaign he bought captured Lithuanian women and children and took them back to Königsberg for their conversion. King Henry's second expedition to Lithuania in 1392 illustrates the financial benefits of these guest crusaders to the Order. His small army consisted of over 100 men, including longbow archers and six minstrels, at a total cost to the Lancastrian purse of £4,360. Despite the efforts of Bolingbroke and his English crusaders, two years of attacks on Vilnius proved fruitless.Vilnius was the flourishing capital of the Grand Duchy of Lithuania, the residence of the Grand Duke. Gediminas expanded the Grand Duchy through warfare along with strategic alliances and marriages. At its height it covered the territory of modern-day Lithuania, Belarus, Ukraine, Transnistria, and portions of modern-day Poland and Russia. His grandchildren Vytautas the Great and Jogaila, however, fought civil wars. During the Lithuanian Civil War of 1389–1392, Vytautas besieged and razed the city in an attempt to wrest control from Jogaila. The two Gediminids cousins later settled their differences; after a series of treaties culminating in the 1569 Union of Lublin, the Polish–Lithuanian Commonwealth was formed. The Commonwealth's rulers held two titles: Grand Duke of Lithuania and King of Poland. In 1387, Jogaila acting as a Grand Duke of Lithuania and King of Poland, granted Magdeburg rights to the city.