 
 <prompt> CHAPTER XVIII. THE ZENITH 

Andrea Doria no remain make formal surrender of the citadel of Sinigaglia to the duke--for which purpose, make we remember, if Cesare bin dey invited, indirectly, to come Sinigaglia. E run comot during the night wey Vitelli and Oliverotto dey struggle for their last for the strangler's hands. And im flight add colour to the versions of the matter wey Cesare and im papa give the world. Andrea Doria, wey dey wait to surrender im trust, no get anything to fear from the duke, no reason to do anything but remain. Andrea Doria, wey dey plot against the duke's life with the condottieri, wey find say dem don seize dem by the duke, and come reason say everything don dey discovered, get every reason to run. 

The citadel surrender on that New Year's morning, when Cesare call am make e do so, while the troops of the Orsini and Vitelli wey dey lodge for the castles of the territory, wey dem catch unawares, dem quickly settle them. So, as nothing dey left to do for Sinigaglia, Cesare once more gather im men and waka go Città di Castello--the tyranny of the Vitelli, wey e find say e no get defense and wey e take possession of in the name of the Church. From there e rush go towards Perugia, because e get information say Guidobaldo of Urbino, Fabio Orsini, Annibale and Venanzio Varano, and Vitelli's nephew dey gather there under the protection of Gianpaolo Baglioni, wey get plenty condotta for im back, and wey dey make big talk say dem go resist the Duke of Romagna and Valentinois. For this matter, Gianpaolo persist bravely until e hear say the duke dey as near as Gualdo, then e quickly run comot--leave im guests make dem find their way. E fit be say e remember, maybe, at the last minute how e narrowly escape for Sinigaglia, and e go Siena go join Pandolfo Petrucci, wey also lucky for that matter. 

Based on the article and the following list of answers, write a list of questions.

1. to take the citadel

Numbered questions: <response>: ```1. Why dem invite Cesare?``` 