The beginnings of Ellwangen Palace reach back to the Late Romantic era. Prince Abbot Kuno I had a well-fortified castle with a palace, a strong western tower and in the east a kind of "antecastle" formed by a group of buildings built in place of a St. Michael's Chaple. Today heavy Staufer rusticated ashlars still remind visitors of the ring wall and a Romanesque gate with a round arch located north of the Michael's Tower (Michaelsturm) on this era.
Late Renaissance
In 1603-1608 Prince Provost Johann Christoph I of Westerstetten had the castle converted to a fortified residential palace in the style of the bishop's mountain palaces in Würzburg and Eichstätt. The four-wing Renaissance palace complex, which originally had dome-crowned corner tower ornaments encompasses a trapezoidal inner courtyard with three-sided, three-story arcades. The palace courtyard with its originally open access galleries with Tuscan and Ionic columns was considered a peculiarity in Swabian palace construction of the Renaissance.
Ornamentation of the Late Renaissance period can also be seen on the carved wooden pulpit of the Palace Chapel (Schlosskapelle) of St . Wendelin.
Baroque
The prince provosts Franz Ludwig of the Palatinate and Franz Georg of Schönborn were the initiators of the remodeling of the palace in the style of the Baroque. Between 1720 and 1727 the palace was transformed into a representative Baroque building with a uniform mansard roof and a large staircase. The position of building supervisor was held until 1724 by the architect of the Teutonic Order (Deutschorden) Franz Keller. Franz Ludwig had the south wing enlarged with a hall and private apartments.
The staircase with access to the main floor (Beletage) was completed according to a design of Franz Keller in 1726. It has Baroque carvings, delicate stuccowork with leaf and ribbon-work from the hand of Franz Joseph Roth and a ceiling fresco by Christoph Thomas Scheffler from 1729/30 with an allegory of the heavenly protection of Ellwangen. The ceiling paining of the Prince's Hall (Fürstensaal) covering two floors is also by Scheffler (1728). it shows how Franz Ludwig is presented with the plans of the new palace.