A petition for the formation of Penllergaer lodge was sponsored by The Corinthian Lodge No. 4917, Brethren from Indefatigable; Talbot; Beaufort and Caradoc lodges being also numbered among the 40 founder members. The Warrant of the Lodge was signed on August 10th. 1935, and the consecration ceremony took place at The Masonic Hall St. Helens Road, Swansea on September 24th. of that year, bringing the number of Swansea lodges to ten. The Lodge derives its name from the estate of Sir Charles Leyshon Dillwyn Venables Llewelyn the then Grand Master of the Eastern Division of the South Wales Province.

The ceremony of consecration was carried out by The Provincial Grand Master who installed the Deputy Provincial Grand Master, W. Bro. E. G. Rutter P.G. D. as the first Master of the lodge. Among the distinguished founder members was Sir William J. Firth who generously donated the banner, which was presented to the lodge at the first regular meeting in November 1935. The banner, designed by a Miss E. M. Hall, is derived from the armorial escutcheon of Sir Charles L. D. Venables Llewelyn and is in the form of a quartered shield. The first and fourth quarters are taken from the Arms of the Llewelyn family, the second and third quarters belonging to those of Dillwyn. The motifs are representative of the unity of Agriculture and Industry. The Motto "OFNA GYWILYDD" is taken from the Latin inscription on the original escutcheon and is translated as 'FEAR SHAME'.