Editing Henry I of England (section)

=== Treaty of Alton, 1101–1102 ===
[[File:Henry I Cotton Claudius D. ii, f. 45v..jpg|thumb|upright=1.4|Early 14th-century depiction of Henry]]

By early 1101, Henry's new regime was established and functioning, but many of the Anglo-Norman elite still supported his brother Robert, or would be prepared to switch sides if Robert appeared likely to gain power in England.<ref>{{harvnb|Hollister|2003|pp=132–133}}; {{harvnb|Green|2009|p=61}}</ref> In February, Flambard escaped from the Tower of London and crossed the Channel to Normandy, where he injected fresh direction and energy to Robert's attempts to mobilise an invasion force.<ref>{{harvnb|Hollister|2003|pp=133–134}}</ref> By July, Robert had formed an army and a fleet, ready to move against Henry in England.<ref>{{harvnb|Hollister|2003|pp=134–135}}</ref> Raising the stakes in the conflict, Henry seized Flambard's lands and, with the support of Anselm, Flambard was removed from his position as bishop.<ref>{{harvnb|Hollister|2003|pp=135–136}}</ref> The King held court in April and June, where the nobility renewed their oaths of allegiance to him, but their support still appeared partial and shaky.<ref>{{harvnb|Hollister|2003|p=125}}</ref>

With the invasion imminent, Henry mobilised his forces and fleet outside [[Pevensey]], close to Robert's anticipated landing site, training some of them personally in how to counter cavalry charges.<ref>{{harvnb|Hollister|2003|p=137}}; {{harvnb|Green|2009|p=63}}</ref> Despite English levies and knights owing military service to the Church arriving in considerable numbers, many of his barons did not appear.<ref>{{harvnb|Hollister|2003|p=137}}</ref> Anselm intervened with some of the doubters, emphasising the religious importance of their loyalty to Henry.<ref>{{harvnb|Hollister|2003|pp=137–138}}</ref> Robert unexpectedly landed further up the coast at [[Portsmouth]] on 20 July with a modest force of a few hundred men, but these were quickly joined by many of the barons in England.<ref>{{harvnb|Hollister|2003|p=138}}</ref> Instead of marching into nearby Winchester and seizing Henry's treasury, Robert paused, giving Henry time to march west and intercept the invasion force.<ref name=Hollister2003PP139>{{harvnb|Hollister|2003|pp=139–140}}</ref>

The two armies met at [[Alton, Hampshire]], where peace negotiations began, possibly initiated by either Henry or Robert, and probably supported by Flambard.<ref name=Hollister2003PP139/> The brothers then agreed to the [[Treaty of Alton]], under which Robert released Henry from his oath of homage and recognised him as king; Henry renounced his claims on western Normandy, except for Domfront, and agreed to pay Robert £2,000 a year for life; if either brother died without a male heir, the other would inherit his lands; the barons whose lands had been seized by either the King or the Duke for supporting his rival would have them returned, and Flambard would be reinstated as bishop; the two brothers would campaign together to defend their territories in Normandy.<ref>{{harvnb|Hollister|2003|pp=142–143}}</ref>{{refn|Most chroniclers reported this sum as 3,000 [[Mark (money)|marks]], equivalent to £2,000, but Orderic recorded the agreed amount as £3,000.<ref>{{harvnb|Green|2009|p=64}}</ref>|group=nb}} Robert remained in England for a few months more with Henry before returning to Normandy.<ref>{{harvnb|Hollister|2003|p=145}}</ref>

Despite the treaty, Henry set about inflicting severe penalties on the barons who had stood against him during the invasion.<ref>{{harvnb|Hollister|2003|p=143}}</ref> [[William de Warenne, 2nd Earl of Surrey|William de Warenne]], the [[Earl of Surrey]], was accused of fresh crimes, which were not covered by the Alton amnesty, and was banished from England.<ref>{{harvnb|Hollister|2003|pp=143–144}}</ref> In 1102 Henry then turned against Robert of Bellême and his brothers, the most powerful of the barons, accusing him of 45 different offences.<ref>{{harvnb|Hollister|2003|p=157}}</ref> Robert escaped and took up arms against Henry.<ref>{{harvnb|Hollister|2003|pp=157–158}}</ref> Henry besieged Robert's castles at [[Arundel Castle|Arundel]], [[Tickhill Castle|Tickhill]] and [[Shrewsbury Castle|Shrewsbury]], pushing down into the south-west to attack [[Bridgnorth]].<ref>{{harvnb|Hollister|2003|pp=158–162}}</ref> His power base in England broken, Robert accepted Henry's offer of banishment and left the country for Normandy.<ref>{{harvnb|Hollister|2003|pp=164–165}}</ref>