LTKada pastatyti Vilniaus Žemutinės pilies (toliau - VŽP) rūmai - nežinoma. Rašytiniai šaltiniai apie tai neužsimena, o kitų duomenų iki archeologinių tyrimų pradžios nebuvo. Rašytiniai šaltiniai ir ikonografinė medžiaga rodo, kad VŽP rūmai XVI a. pradžioje buvo perstatyti j renesansinio stiliaus keturių korpusų mūrinį pastatą, stovėjusį VŽP centre - tarp Katedros ir Gedimino pilies kalno. Manoma, kad jie statyti buvusių senesnių rūmų vietoje. Kartais spėliota, kad pirmus mūrinius VŽP valdovų rūmus bus pastatęs Kazimieras Jogailaitis (1440-1492) ar Aleksandras Jogailaitis (1492-1506). Tik paskutiniu metu pradėta kelti hipotezė, kad senuosius' rūmus bus pastatęs didysis kunigaikštis Vytautas. „Tuo metu (t.y. po 1419 m. gaisro - A.K.) turėjo iškilti nauji ar perstatyti senieji kunigaikščių rūmai, bent ne mažesni kaip Trakų salos pilies rūmai, nes čia numatytos Vytauto vainikavimosi iškilmės, kurioms reikalinga ir katedra, ir rūmų salė bei patalpos svečiams”. [Iš teksto, p. 215].
ENWritten records on this subject are scarce. Before archaeological investigations were carried out in the Vilnius Lower Castle, it was know that in the 16th century the Lower Castle had been reconstructed as part of the Renaissance brick palace complex of four buildings. At that time the palace occupied the area between Gediminas Castle Hill and the Cathedral. Systematic investigations of the Lower Castle were begun in 1988. The eastern building, about a half of the southern palace and some parts of the inner and outer courtyards have .already been investigated. The excavation records point to the fact that the palace within Vilnius Lower Castle was already standing the reign of Grand Duke Vytautas (1392-1430). Different finds, such as decorative bricks, mortar, stove tiles etc., show that the palace was rebuilt in the Gothic style. Like the 16th - 17th c. palace, Vytautas' palace occupied the natural outcrop situated between Gediminas Castle Hill and the Cathedra). The outcrop is a sandy hillock, 40 m wide, the slopes of which are about 7 m high. In the 15th. c. the layout of the palace was, for the most part, already established: the eastern and southern wings along with the ramparts and buttresses which had already been erected on the northern slope of the outcrop, enclosed the inner courtyard.The Gothic palace was built of brick without a plaster facade. The eastern building had cellars and, above ground, at least two storeys. This building was about 40 m long and about 10 m wide. Approximately half of the supposed length of the southern building has been uncovered, i.e. from the boundary with the eastern wing as far as the Cathedral. Archaeological investigations have provided more specific information about the appearance of the palace and given details that would help to reconstruct its surroundings. It was discovered that the walls of the palace were covered with ceramic, sometimes glazed tiles; the windows were of stained-glass; the interiors of some buildings were plastered and decorated with frescoes; there were splendid "Dutch" tile stoves in the palace. The remnants of a wall dating from the 13th 14th centuries point to the fact that already in the 14th c. some brick buildings stood on the site later occupied by the palace in Vilnius Lower Castle.