Peter succeeded to the whole of his father's kingdom on the latter's death while besieging
Huesca in 1094. Peter raised the siege, only to return to it within the year. After 1094 his objectives shifted westwards, towards the valley of the
Gallega. In 1095 Peter renewed his father's oaths to
Urban II, and Urban renewed his promise of protection, under which Sancho, his sons, and his kingdom had been placed in July 1089. On 16 March 1095 the pope even issued a
bull,
Cum universis sancte, granting the king and queen of Aragon immunity from
excommunication without the permission of the pope. That same year, while he was besieging Huesca, Peter defeated the relief forces of the
Taifa of Zaragoza at the
Battle of Alcoraz. Peter later rewarded a certain Sancho Crispo for his contribution of three hundred knights and infantry at Alcoraz. He went on to take Huesca on 27 November of that same year.
Reconquista and war with the Almoravids . According to legend, George appeared on the field of battle at Alcoraz. The heads of four decapitated Moors found on the battlefield were added to George's familiar emblem, creating the
Cross of Alcoraz (the basis for the
Sardinian coat-of-arms). The next year (1096) Peter travelled south to inspect his fortress at
Castellón, though the
Historia Roderici claims that he came to help Rodrigo. He met Rodrigo in Valencia and with a large force already assembled they decided to reinforce the southern frontier fort of Benicadell, rebuilt by Rodrigo in 1091. As they were passing by
Xàtiva they were met by an Almoravid force under the command of Mohammed, the nephew of Almoravid leader
Yusuf ibn Tashfin, and the commander whom Rodrigo had defeated at the
Battle of Cuarte in 1095. They decided to hastily restock Benicadell and retreat to Valencia via the coast, but were met at the
Battle of Bairén by Muhammad's forces encamped on the high ground that reached almost to the sea. A small Almoravid fleet had been assembled from the southern ports, including
Almería, and the Christians were trapped between arrow fire from the ships and the cavalry perched atop the hill. Rodrigo roused the troops with a speech and the next day at midday the Christians charged. The
Battle of Xàtiva ended in a rout, with many Almoravids killed or forced into the river or the sea, where many drowned. Peter and Rodrigo returned to Valencia in triumph and thanking God for the victory, as the
Historia records. certainly did make war on Zaragoza in 1101, in a campaign that lasted the whole year. He may have been inspired by the
First Crusaders, since contemporary accounts of the 1101 campaign call him a "cross-bearer" (
crucifer). The size of his forces so impressed a contemporary scribe in
León that he remarked in the dating formula of a document of 12 February that "Peter, Aragonese king, with his infinite multitude of armed men, the city of Zaragoza, with Christ's banner, fought". By June Peter had begun the siege of
Zaragoza itself. For the siege he had a fortress built named
Juslibol (a corruption of the Latin slogan
Deus lo volt [God wills it] used by the First Crusaders) and ringed the city with banners bearing the cross. In August he was conducting a
razzia (raid) as far south as
Alpenes and the
river Ebro, but the campaign was eventually aborted due to insufficient cavalry. On 11 December 1102 Peter was in
Estella on the border with
Castile, perhaps seeking the aid of
Alfonso VI after a particularly disastrous autumn for the Christians of eastern Spain. In 1104 Peter granted a
fuero to all the
infanzones of his realm, retaining his right to require three-day field service. ==Succession==