Item pro calce¹     viii s. vii d.
1340 liberat' I. Gildene Cementario pro 
             opere ecclesie         xv d.
1341 Item Iohanni Gildene et sociis suis pro 
             diversis operibus.    iii s. ii d.

   Extensive alterations to the Cathedral, including the rebuilding of the nave, had been determined upon before 1377, and in that or the following year the foundations of the aisle walls were laid. It is usually held that the death of Archbishop Simon Sudbury at the hands of the rebels in 1381 was the principal cause of the stoppage of work between 1383 and the election of Prior Chillenden in 1391. Probably the immediate cause of the break was the occurrence of a severe earthquake shock on the 21st of May 1382, for the Treasurers' Accounts show extensive damage to the monastic buildings:—

Treasurers' Accounts, xv. 2.
1382/3 In expensis circa fabricam ecclesie per manus Iohannis Godnyston custodis novi operis     lxxvi li x s.
In diversis expensis circa le malthalle hoc 
        anno de novo faciendo (sic)     cxxiiii li. ii s. viii d. ob.
In plena solucione cariagii meremii per 
       Thomam Longe per aquam       x li.
Opera infra curiam vii li. iiii s. v d. et tantum causa
       terremotus.

1383/4 Et in reparacione molendini Berthone 
      cum petris de Folkestone et Carpent' cum 
       novis bordyis factis        vii li. xvii s. v d.
Et in reparacione Capelle Infirmarie ex parte 
       boriali per terremotum destructe    xi li. xiiii s. vi d.
Et in reparacione lotorii² prioris et lotorii claustri 
       et muri claustri ab ostio Capituli usque ostium
       dormitorii per terremotum destructi        vii li. xix s.
Et in novo tecto facto ultra martirium beati Thome
       cum plumbo empto in partem solucionis³  x li. x s. v d.
Et in nova clausura ferrea sub magnis organis⁴ 
         per manus Iohannis Godenyston           xxxi li. xx d.

During the building of the nave between 1391 and 1400 Master Henry Yevele, the King's Chief Mason, seems to have been retained by Prior Chillenden, and his name occurs in the only surviving Prior's account of this period:— 

Prior's Account Roll, xvii. 4.
1396/7 Fabrica Ecclesie In xx latomis et iii leggeres (5) et iiii laborariis
   ¹  Lime
    ²  Lavatory.
    ³  In part payment.
    ⁴  Iron screen beneath the great organs.
    ⁵  Layers or setters of stone.