The following is from http://midgleywebpages.com/thornhill.html concerning the Thornhill & Fixby families:

John is known from the Nomina Villarum of 1316 to have held East Bierley and also the manor of Shelf before Sir William de Miggeley. [N.V. 1867, p. 361.] According to http://www.bretton.org/documents/The%20Bretton%20-%20Wentworth%20Tree.doc he died in Austria-Hungary, fighting the Islamic Turks of The Ottoman Empire. He was married in 1310 at Thornhill to Beatrice Taboner/ Talboner b. ca. 1270, they had six children, she died after 1327 in Austria-Hungary at the beginning of Edward III's reign. She was certainly dead by 1329 when her dower in Wadsworth was enfeoffed by her brother-in-law Brian de Thornhill rector of Bedale to John de Methley his brother-in-law. In 1327 there was also a crusade planned by the Knights Hospitallers against the Cathars in Hungary. John was a Knight of Rhodes or a Hospitaller. Also at this time during Edward II's reign [1307-1327] the Thornhills married into the Babthorpes. John appears earlier in the Wharncliffe Muniments where he was a witness to a deed for Nicholas de Wortley of Wortley between 1295 and 1300. He is also mentioned in the C.P.R. a number of times in Edward II's reign as a commissioner of oyer and terminer [25th Sept 1318; 2nd Sept 1320] but not in Edward III's reign, thus flourishing in Edward II's reign. In 1317 he was granted a market and fair at Thonhill as well as free warren here and at 'Hundesworth', 'Birle', Gomersall and Cleckheaton by Edward II at the request of John de Warrene19 and in 1321 held the wardship of Richard de Tonge also granted by the king. These appointments and grants all suggest that, like his neighbour William de Miggeley, he was King Edward II's man throughout most of the rebellion of Thomas earl of Lancaster. The only evidence to show that he wavered was when he was pardoned on 20 August 1321 at York with many others for his actions against Hugh le Despenser, the son and father, between 1 March and 19 August 1321. He was pardoned on the testimony of John de Warrene earl of Surrey, Lord of Wakefield. On the 8th October 1321 he is recorded as having entered the dwelling of Hawisa, widow of Walter de Gloucester at 'Haidore' [Haydor] Lincs. with Walter's two sons and many others wherein they drove her livestock away and stole her jewellery.11 His death in 15Ed.II [1322] showed that he was also seised of the manor of Foulridge in Whalley. He is mentioned in a Parliamentary writ for 25th March 1322, three days after the execution of earl Thomas of Lancaster at Pontefract when he was given commission to raise 4000 footmen in parts of Yorkshire for a Scottish campaign which proved a near disaster. It is possible that the chain-mailed and life-like effigy, in Thornhill Parish Church dedicated to St. Michael and All Angels, is that of John.

In the C.P.R. there is also made mention of a John de Methley [Metheleye / Metheleye] of Thornhill who held the manor of Methley. This John de Methley was a brother-in-law to John de Thornhill after he married Cecily de Thornhill in abt. 1320, William's sister. John de Methley was pardoned in 1313 for his part in the death of Piers Gaveston, and later whilst the king was visiting the manors of the defeated rebels, John was described as a 'king's yeoman' pardoned on the 8th June 1323 for being involved in Lancaster's rebellion. In 1326 John de Methley was pardoned for acquiring in fee from Adam de Everyngham of Laxton the manor of Middle Sitlington [Middlestown], 'held in chief as of the honour of Pontefract, and entering therein without licence; with restitution of the same. Adam de Everingham is related back to a common ancestor, Adam FitzPeter, grandson of Essulf, with Sir William de Miggeley, a contemporary.

There is a also 'Richard de Thornhille'/Thornhill, possibly kindred to John, who was pardoned at Westminster Hall in 1313 for his part in the death of Piers Gaveston and at York in 1318 for being an adherent of earl Thomas of Lancaster. If this man was a relation of John de Thornhill's, then like a number of northern families at this time, they were divided over their loyalties between earl Thomas and Edward II.