These brothers came from San Severino in the Marches and were proponents of the International Gothic.   The more senior, Lorenzo, is first documented in the signed triptych (1400) of the Coronation of the Virgin from the church of San Lorenzo in Doliolo, San Severino, which is now in the Pinacoteca there.  A number of other signed works by Lorenzo alone survive, together with two signed by both brothers:

1. ✴the frescoes (ca. 1406) of scenes from the life of St John the Evangelist in the Duomo Vecchio, San Severino (signed by “Lorenzo e Jachomo so fratello”; and
   

2. ✴the frescoes (1416) of the Crucifixion and scenes from the life of St John the Baptist in the Oratorio di San Giovanni, Urbino, signed by “Laure[n]tus da Santo Se[ver] ino et Jacobus [frater eius”].
   

No surviving work can be securely attributed to Jacopo alone and none of those securely attributed to Lorenzo post-date 1416.

Gubbio

St Michael (ca. 1410)

This fresco, which was rediscovered under plaster in ca. 1930 on the counter-facade of Santa Maria Nuova, is attributed to Lorenzo Salimbeni.  (Mauro Minardi, referenced below, supports this attribution, but points out that other scholars believe that it post-dates Lorenzo’s death and therefore attribute it to Jacopo).

Last Judgement (early 15th century)

This fresco on the chancel arch of Sant’ Agostino was rediscovered in the restoration of 1901.  It was restored again on two occasions: in 1965; and in 2003.  It seems that the fresco was executed in two phases:

1. ✴The upper part of the fresco, which depicts Christ in Judgement, with Apostles enthroned to the sides and kneeling saints below them, is attributed to Ottaviano Nelli and his workshop. 
   

2. ✴The lower part,which is attributed to one or both of Lorenzo and Jacopo Salimbeni  working with (and probably under) Ottaviano Nelli, includes: the resurrection of the dead (at the centre); the reception of the saved by SS Peter and Paul and the celestial vision (on the right); and the descent of the damned into Hell (on the left).
   

Fabrizio Cece and Ettore Sannipoli (referenced in the page on the church) suggest that the lower part of the fresco was painted after the death of Lorenzo Salimbeni in 1420 and therefore attribute it largely to his brother Jacopo.  Mauro Minardi (referenced below) believes that it was painted in ca. 1410 and attributes it to Lorenzo Salimbeni.

Norcia

Madonna and Child with saints (ca. 1417)

This damaged fresco in Santa Scolastica (to the right of the presbytery arch), which is attributed to Lorenzo Salimbeni, depicts the Madonna and Child enthroned and crowned by two angels, with SS Benedict and John the Baptist to the sides.  There is also a fragmentary figure of St James to the left, but the balancing saint on the right (perhaps St Scholastica) is missing.  The fresco was rediscovered under plaster in 1978.  The dating of Mauro Minardi (referenced below) is made on stylistic grounds, but also corresponds to the reconsecration of the church in 1417.  His attribution is to Lorenzo alone, although other scholars give the work to both Lorenzo and Jacopo Salimbeni.

Perugia

Crucifixion (ca. 1410)

1. ✴the swooning Virgin, the distraught St Mary Magdalene and other women to the left; and
   

2. ✴the weeping St John the Evangelist on a rock to the right.
   

[Note that the attribution and dating here are suggested by Mauro Minardi, cited below.  The Galleria Nazionale dates the work to ca. 1416-20 and attributes it to Jacopo Salimbeni.]