▁last ed ▁many ▁dec ades . ▁The ▁attack ers ▁were ▁not ▁" p ir ates " ▁as ▁often ▁character ised , ▁though ▁some ▁may ▁have ▁been ▁mer cen aries ▁from ▁North ▁Africa . ▁The ▁campaign s ▁were ▁conducted ▁on ▁the ▁direct ▁orders ▁of ▁Sultan ▁S ule iman . ▁The ▁attack ▁led ▁to ▁the ▁construction ▁of ▁a ▁new ▁line ▁of ▁walls . ▁The ▁most ▁striking ▁event ▁of ▁the ▁following ▁century ▁was ▁the ▁revol t ▁against ▁Spanish ▁dom ination ▁of ▁ 1 6 4 8 , ▁led ▁by ▁Giovanni ▁Gr illo . ▁In ▁ 1 6 5 6 ▁a ▁pl ague ▁struck ▁the ▁city . ▁However , ▁Sor rent o ▁remained ▁one ▁of ▁the ▁most ▁important ▁cent res ▁of ▁southern ▁Camp ania . ▁ ▁Sor rent o ▁entered ▁into ▁the ▁Ne ap ol itan ▁Republic ▁of ▁ 1 7 9 9 , ▁but ▁in ▁vain . ▁In ▁the ▁ 1 9 th ▁century ▁the ▁economy ▁of ▁the ▁city ▁improved ▁marked ly , ▁fav oured ▁by ▁the ▁development ▁of ▁agricult ure , ▁tour ism ▁and ▁trade . ▁A ▁route ▁connecting ▁Sor rent o ▁to ▁Cast ell amm are ▁di ▁St ab ia ▁was ▁opened ▁under ▁the ▁reign ▁of ▁Ferdinand ▁II ▁( 1 8 3 0 – 1 8 5 9 ). ▁ ▁In ▁ 1 8 6 1 ▁Sor rent o ▁was ▁officially ▁an nex ed ▁to ▁the ▁new ▁Kingdom ▁of ▁Italy . ▁In ▁the ▁following ▁years ▁it ▁confirmed ▁and ▁increased ▁its ▁status ▁of ▁one ▁of ▁the ▁most ▁ren owned ▁tour ist ▁destin ations ▁of ▁Italy