  pope saint leo iv (790 â 17 july 855) was pope from 10 april 847 to his death in 855. ==life== a roman by birth, he was unanimously chosen to succeed sergius ii. when he was elected, on 10 april 847, he was cardinal of santi quattro coronati and had been subdeacon of gregory iv and archpriest under his predecessor. his pontificate was chiefly distinguished by his efforts to repair the damage done by the saracens during the reign of his predecessor to various churches of the city, especially those of st peter and st paul. the saracens were besieging gaeta, which led to leo's order that the walls of the city be restored and strengthened between 848 and 849. when the muslims approached portus, he summoned the repubbliche marinare (or mariner cities of italy) â naples, gaeta and amalfi â to form a league. the command of the unified fleet was given to cesarius, son of duke sergius i of naples. the subsequent battle of ostia was one of the most famous in history of the papacy of the middle ages and is celebrated in a famous fresco by raphael and his pupils in his rooms of the vatican palace in the vatican city. another episode of leo's life celebrated by the urbinate in his series of frescoes for the incendio di borgo is the burning of the pilgrims' district of rome (the "borgo"), which, according to the legend, was stopped by leo simply making the sign of the cross. thumb|left|upright|the battle of ostia in an 1829 engraving. in order to counter the saracen menace definitively, leo ordered a new line of walls encompassing the suburb on the right bank of the tiber to be built, including st. peter's basilica, which had been undefended until this time. the district enclosed by the walls is still known as the leonine city, and corrensponds to the later rione of borgo. he also restored and embellished the damaged basilica di san paolo fuori le mura and st. peter's: the latter's altar again received its gold covering (after being stolen), which weighed 206&nbsp;lb. and was studded with precious gems. following the restoration of st. p
855_deaths 9th-century_Christian_saints 9th-century_Italian_people 9th-century_archbishops Italian_popes Papal_saints People_of_medieval_Rome Popes