The importance of Clane continued after the Norman settlement. Gerald Fitzmaurice Fitzgerald, Lord of Offaley, established the Franciscans here in 1258. The establishment was well endowed with land and property and very extensive ruins remain to the present day at the Abbey Cemetery on the Naas Road. A general chapter was held here in 1345. It was finally suppressed in 1540 during the reign of Henry VIII. Clane was a town of the Pale, which was established by an act of the Parliament of Drogheda in 1488, the bounds of which were thus traced: "From Merrion, inclusive, to the waters of the Dodder, by the new ditch to Saggart, Rathcoole, Kilheel, (Kilteel), Rathmore and Ballymore (Eustace). Thence to the county of Kildare into Ballycutlan, Harristown and Naas, and so thence of Clane, Kilboyne and Kilcock. From Kilcock it ran to Athboy and so ended at Dundalk". Stretches of the Pale embankment survive at Clongowes and further north about half way to Kilcock.

Administratively, Clane was a Corporate Town with its own chapter and the modern equivalent of a Mayor and Corporation. From the Rolls we find that on 14th March 1391, the King granted to the Provost, Bailiffs and the Commonality of the town of Clane, that for seven years they may make custom of goods coming to the town and build anew a certain bridge of the said town over the water of the Analiffey. The bridge in question stood in fact until 1862 when it was replaced by the present structure. Again in 1417, we find a letter addressed to King Henry V on behalf of Lord Furnivall, dated 26th June. Among the signatories are found the Commons of Clane. Another letter dated the 23rd January 1454 is signed, among others, by the Portrives and Commons of Clane. The original is still intact in the British Museum with many pendant seals. (Cottonian MSS). It is the intention of the Community Council shortly to reactivate our rights under this ancient Charter and re-inaugurate the office of Mayor in Clane.