Many considerations suggest the likelihood that the first Roman walled city was smaller in extent than it became at a later time. Roach Smith thought that this earlier city was confined to the east side of the Walbrook, the approach from London Bridge forming its centre. The great wall, according to him, was "probably a work of the later days of the Romano-British period." With this view J. R. Green agrees, and argues that the wall was built in haste under Theodosius, when the attacks of Picts and Saxons made walls necessary for the security of British towns.[76] Henry of Huntingdon, writing early in the twelfth century, tells us that "tradition says that Helen, the illustrious daughter of Britain, surrounded London with the wall which is still standing." * * * * * _Gates._--Opposite the entrance to the city by the bridge was the _North Gate_, called Bishopsgate. According to Geoffrey of Monmouth, Cæsar's sword "Yellow Death" was buried here with a Briton who had been slain by it. This legend is at least enough to show that the gate was ancient at the beginning of the twelfth century. Bishopsgate is mentioned in Domesday: "The canons of St. Paul's have _ad portam episcopi_ ten cottages as in the time of King Edward." Outside the gate the Erming Street stretched away to the north over the moor. The _East Gate_--Aldgate (generally written Algate or Alegate)--is mentioned in the foundation charters of Holy Trinity Priory in 1108. Stow says he found it named in a charter given by King Edgar to the Cnihten Gild, but it seems that he founded this on a later legend which professed to recite the terms of such a charter. However, the Saxon Chronicle, giving an account of the dispute between the Confessor and Godwine in 1052, says that some of the Earl's party _gewendon ut æt Æst geate_ and got them to Eldulfsness (Walton-on-the-Naze). Mr. W. H. Stevenson, in an interesting note on personal names associated with town gates, cites an eleventh-century life of St. Edmund, in which it is called Ealsegate, and suggests that it may be named from one Ealh; the East Gate of Gloucester was called Ailesgate from Æthel.[77] A survey of Holy Trinity precinct made about 1592, and now at Hatfield, gives the plan of the gate as it then existed (possibly in part Roman), and a length of the city wall with its semicircular bastions.[78] Outside this gate the great Roman road reached away to Chelmsford and Colchester.