Gemma di Napoli

Origins

http://fmg.ac/Projects/MedLands/SOUTHERN%20ITALY,%20PRE-NORMAN.htm#...

ii) ATHANASIUS (-[Mar/Apr] 898). … Devoted to Byzantine culture, he secured and preserved for posterity many Greek manuscripts[1876].

m ---. The name of Athanasius´s wife is not known. Athanasius & his wife had two children:

• (a) GEMMA (-after 10 Jul 961). The Chronicon Salernitanum records that "Athanasii filiam…Gemma" married "Atenolfi filius…Landolfus", dated to [Jan/Feb] 898 from the context[1877]. The Chronicon Vulturnense records "Landolfus et Pandolfus filius eiusdem…Langobardorum gentis" confirmed the grant of fishery rights "in lacum Patrensem" to the monastery of Volturno, granted by "domna Gemma principissa…genitrice nostra", by charter dated 960[1878]. Pandulf I and Landulf III Princes of Capua confirmed territory at Larino to Monte Cassino, at the request of "domna Gemma religiosa principessa abia nostra", by charter dated 10 Jul 961[1879]. m ([Jan/Feb] 898) LANDOLF of Capua, son of ATENOLF I Count of Capua, Prince of Benevento & his wife ---. He succeeded his father in 910 as LANDOLF III Prince of Capua.
• (b) EUPRASSIA (-before 30 Jan 970). A charter dated 30 Jan 970 recalls a donation by "q. d. Eupraxia h. f. filia d. Athanasii episcopi…cum voluntate d. Stephani militis viri sui"[1880]. m STEFANO, son of ---.

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Family

http://fmg.ac/Projects/MedLands/SOUTHERN%20ITALY,%20PRE-NORMAN.htm#...

Atenolf & his first wife had two children:
1. LANDOLF (-943). … he succeeded his father in 912 as LANDOLF III joint Prince of Capua and Benevento, jointly with "Atenulfo germano suo et filii eorum"[1538]. …

m ([Jan/Feb] 898) GEMMA of Naples, daughter of ATHANASIUS Duke of Naples & his wife --- (-after 10 Jul 961).

Prince Landolf & his wife had two children:

• a) ATENOLF (-943). … m ( [925] ) ROTILDA di Salerno, daughter of GUAIMAR II Prince of Salerno & his first wife --- (-after 954). The Chronicon Salernitanum records that "Atenolfus Beneventanus princeps" married "Guaimarius…sua filia Rothilda"[1552]. Atenolf III & his wife had [two or more] children:
• b) LANDOLF (-961). According to the "Catalogus Principum Capuæ", "Atenulfus III et Landulfus II, filii Landulfi" ruled jointly with their father[1554]. He succeeded his brother in 943 as LANDOLF IV Prince of Capua and Benevento. - see below. m ([935]) ---.

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The old unsourced birth date c.895 seems somewhat random, given the sourced marriage exactly 898.

PLZ source, explanation, or calculations TNX