Ulrich I, Count of Cilli was born circa 1331 to Frederick I, Count of Cilli (c1295-1359) and Diemut von Walsee (c1305-c1357) and died 1368 of unspecified causes.
Ulrich was a war contractor and mercenary leader in the grand style of the type of a real condottiere. He made his mercenaries available to anyone who needed them, paid them well and engaged them where he saw the greatest benefits for them. Ulrich was present on all the battlefields of Central and Eastern Europe. In 1354 he accompanied Emperor Charles IV to Rome. Ulrich and his troops fought side on the battlefields of Dalmatia, Serbia and Bulgaria. In Tyrol he fought shoulder to shoulder with the Wittelsbach family.
Soon his military operations led him far to the north, where he fought against the pagan Prussians. In 1355, he was back on the side of Louis I of Hungary in the fight against Venice and in 1359 he participated in the campaign against Serbia.
His campaigns gave Ulrich the opportunity to have close relationships with the leaders of Central Europe and the Cilli family gradually became extremely important. Ulrich's wife was Adelheid of Ortenbourg , the widow of Count Albrecht of Oettingen and daughter of Count Hermann of places and the castle Adelheid of Schauenbergstrasse. Their son William of Cilli, his father's mercenary business.
In 1341, Ulrich and his father, who until then wore the name of Sanneck, were elevated to the title of Counts of Cilli (Celje).
Children
| Name | Birth | Death | Joined with |
| William, Count of Cilli (c1361-1392) | 1361 | 1392 | Elizabeth of Görz (c1363-c1373) Anna of Poland (1366-1422) |
Siblings
| Name | Birth | Death | Joined with |
| Ulrich I, Count of Cilli (c1331-1368) | 1331 | 1368 | Adelheid von Ortenburg (c1335-1391) |
| Herman I, Count of Cilli (c1333-1385) | 1333 | 21 March 1385 | Katharina Kotromanić (c1336-c1396) |
| Katarina of Cilli (c1334-1389) | 1334 | 17 July 1389 | Albrecht III, Count of Görz-Lienz (c1308-c1365) Johann II, Truchsess von Waldburg (c1350-1424) |
| Anna of Cilli (c1335-c1354) | |||
Residences
Footnotes (including sources)