I need help translating some text my Grandmother found. Long story short my Grandmother lives in a 13th century house in the French countryside It is a care home, built and rebuilt times beyond counting. However, the tunnels and basement beneath the keep were relatively untouched due to a possibility of high levels of lead. Regardless, the basement or larder, or whatever it's called is now safe, apparently.

My mother and grandmother were exploring the estate and were allowed into the Basement (now storage), when my Grandmother, (despite being blind in one eye) found some message/text engraved onto a wall next to a worn picture of a shield. The shield has a cross on it, maybe English, maybe a holy symbol. Either way, they want the text translated, I can't fucking do it nor can they or anyone there. I don't even know what fucking language it is. I don't like history anyway, and don't particularly give a shite, to be honest.

tl:dr can anyone translate this shit please.

"Miles militis Templum est instituo eram sententia Arcus ruit agnitio meus ultra tuam senio instituo locus Illic Michæ. In Aula est commentariis super Quod dictum est VALDE UT UT harenae Quod Pharos reliquerant. Purissima non fecit sex reverto. Damocles Sire Admiralquod puto duodeviginti habitum robur Insula Vero key trinus in silva pro UT IAM atrum est impossibile est Maiestas Quod suus prohibeo ex suis movin.

Vexillum eruptio ex traba suus Quod senior ligatio Jory sui. Si est nuntius Vos precor reperio Mihi Quis efficio dico quae tunc non teneo UT. Reperio Mihi procul tumulosus Tabellae per ceterus of ero Ordo nonus de. Caput capitis mos Nos occasus quae tunc Romano Monte UT. UT Non Last sub Romano.

Key Atla abscondit depressas impiis

Vos ingredior in May suus gradus.

Pauperes commilitones Christi Templique"