Upon the death of his father Andrea II, his lands were divided among his three sons, Gjin I, Teodor II and Stoya.[3]
Gjin inherited the majority of his father’s holdings, except for Berat, Myzeqe, and Kastoria. Teodor received Berat and Myzeqe, while Stoya inherited Kastoria along with its associated villages and estates.[4]
He died fighting during the Battle of Kosovo in 1389 on the side of the anti-Ottoman coalition led by Lazar of Serbia.[5][6] After his death the rule of his domain passed over to his nephew Teodor III Muzaka. This could only happen because his only son Nicola must have been dead at the time or was held captive by his aunt Comita.[7]
^Elsie, Robert (2003). Early Albania A Reader of Historical Texts, 11th-17th Centuries. Harrassowitz. p. 42. ISBN978-3-4470-4783-8. ...Lord Andrew Musachi, the said second despot, and his wife, Euthymia...
^Elsie, Robert (2003). Early Albania A Reader of Historical Texts, 11th-17th Centuries. Harrassowitz. p. 42. ISBN978-3-4470-4783-8. ...From the said Lord Andrew Molosachi the Despot were born with three sons and two daughters. The first-born was called Lord Gjin, the second Lord Theodore and the third Lord Stoya. Of the daughters, the first one was called Lady Comita Musachi and the second Lady Chiranna....
^Elsie, Robert (2003). Early Albania A Reader of Historical Texts, 11th-17th Centuries. Harrassowitz. p. 42. ISBN978-3-4470-4783-8. ...The first-born was called Lord Gjin, the second Lord Theodore and the third Lord Stoya...
^Elsie, Robert (2003). Early Albania A Reader of Historical Texts, 11th-17th Centuries. Harrassowitz. p. 42. ISBN978-3-4470-4783-8. ...He left all of his land, with the exception of Berat, Myzeqe and Castoria, to his first-born son, Lord Gjin Musachi. To his second son, Lord Theodore, he left Berat and Myzeqe, and to his third son, Lord Stoya, he left Castoria with all the villages and estates belonging to it...
^"1515 | John Musachi: Brief Chronicle on the Descendants of our Musachi Dynasty". Albanianhistory.net. Archived from the original on 10 September 2010. Retrieved 13 February 2012. Lazar (6), the Despot of Serbia, and King Marko of Bulgaria and Theodore Musachi, the second-born of our family, and the other Lords of Albania united and set off for battle, which the Christians lost (7).